Chickenpox

Definition

Chickenpox (also called varicella) is a common and extremely infectious childhood disease that also affects adults on occasion. It produces an itchy, blistery rash that typically lasts about a week and is sometimes accompanied by a fever or other symptoms. A single attack of chickenpox almost always brings lifelong immunity against the disease. Because the symptoms of chickenpox are easily recognized and in most cases merely unpleasant rather than dangerous, treatment can almost always be carried out at home. Severe complications can develop, however, and professional medical attention is essential in some circumstances.

Description

Before the varicella vaccine (Varivax) was released for use in 1995, nearly all of the four million children born each year in the United States contracted chickenpox, resulting in hospitalization in five of every 1,000 cases and 100 deaths. Chickenpox is caused by the varicella-zoster virus (a member of the herpes virus family), which is spread through the air or by direct contact with an infected person. Once someone has been infected with the virus, an incubation period of about 10-21 days passes before symptoms begin. The period during which infected people are able to spread the disease is believed to start one or two days before the rash breaks out and to continue until all the blisters have formed scabs, which usually happens four to 7 days after the rash breaks out but may be longer in adolescents and adults. For this reason, doctors recommend keeping children with chickenpox away from school for about a week. It is not necessary, however, to wait until all the scabs have fallen off.

Chickenpox has been a typical part of growing up for most children in the industrialized world (although this may change if the new varicella vaccine becomes more widely accepted). The disease can strike at any age, but by ages nine or 10 about 80-90% of American children have already been infected. U.S. children living in rural areas and many foreign-born children are less likely to be immune. Because almost every case of chickenpox, no matter how mild, leads to lifelong protection against further attacks, adults account for less than 5% of all cases in the United States. Study results reported by the Centers for Disease Control and Prevention (CDC) indicate that more than 90% of American adults are immune to the chickenpox virus. Adults, however, are much more likely than children to suffer dangerous complications. More than half of all chickenpox deaths occur among adults.

Causes and symptoms

A case of chickenpox usually starts without warning or with only a mild fever and a slight feeling of unwellness. Within a few hours or days small red spots begin to appear on the scalp, neck, or upper half of the trunk. After a further 12-24 hours the spots typically become itchy, fluid-filled bumps called vesicles, which continue to appear in crops for the next two to five days. In any area of skin, lesions of a variety of stages can be seen. These blisters can spread to cover much of the skin, and in some cases also may be found inside the mouth, nose, ears, vagina, or rectum. Some people develop only a few blisters, but in most cases the number reaches 250-500. The blisters soon begin to form scabs and fall off. Scarring usually does not occur unless the blisters have been scratched and become infected. Occasionally a minor and temporary darkening of the skin (called hyperpigmentation ) is noticed around some of the blisters. The degree of itchiness can range from barely noticeable to extreme. Some chickenpox sufferers also have headaches, abdominal pain, or a fever. Full recovery usually takes five to 10 days after the first symptoms appear. Again, the most severe cases of the disease tend to be found among older children and adults.

Although for most people chickenpox is no more than a matter of a few days' discomfort, some groups are at risk for developing complications, the most common of which are bacterial infections of the blisters, pneumonia, dehydration, encephalitis, and hepatitis :

• Infants. Complications occur much more often among children less than one year old than among older children. The threat is greatest to newborns, who are more at risk of death from chickenpox than any other group. Under certain circumstances, children born to mothers who contract chickenpox just prior to delivery face an increased possibility of dangerous consequences, including brain damage and death. If the infection occurs during early pregnancy, there is a small (less than 5%) risk of congenital abnormalities.
• Immunocompromised children. Children whose immune systems have been weakened by a genetic disorder, disease, or medical treatment usually experience the most severe symptoms of any group. They have the second-highest rate of death from chickenpox.
• Adults and children 15 and older. Among this group, the typical symptoms of chickenpox tend to strike with greater force, and the risk of complications is much higher than among young children.

Immediate medical help should always be sought when anyone in these high-risk groups contracts the disease.

Diagnosis

Where children are concerned, especially those with recent exposure to the disease, diagnosis can usually be made at home, by a school nurse, or by a doctor over the telephone if the child's parent or caregiver is unsure that the disease is chickenpox.

A doctor should be called immediately if:

• The child's fever goes above 102 °F (38.9 °C) or takes more than four days to disappear.
• The child's blisters appear infected. Signs of infection include leakage of pus from the blisters or excessive redness, warmth, tenderness, or swelling around the blisters.
• The child seems nervous, confused, unresponsive, or unusually sleepy; complains of a stiff neck or severe headache ; shows signs of poor balance or has trouble walking; finds bright lights hard to look at; is having breathing problems or is coughing a lot; is complaining of chest pain; is vomiting repeatedly; or is having convulsions. These may be signs of Reye's syndrome or encephalitis, two rare but potentially dangerous conditions.

Treatment

With children, treatment usually takes place in the home and focuses on reducing discomfort and fever. Because chickenpox is a viral disease, antibiotics are ineffective against it.

Applying wet compresses or bathing the child in cool or lukewarm water once a day can help the itch. Adding four to eight ounces of baking soda or one or two cups of oatmeal to the bath is a good idea (oatmeal bath packets are sold by pharmacies). Only mild soap should be used in the bath. Patting, not rubbing, is recommended for drying the child off, to prevent irritating the blisters. Calamine lotion (and some other kinds of lotions) also help to reduce itchiness. Because scratching can cause blisters to become infected and lead to scarring, the child's nails should be cut short. Of course, older children need to be warned not to scratch. For babies, light mittens or socks on the hands can help guard against scratching.

If mouth blisters make eating or drinking an unpleasant experience, cold drinks and soft, bland foods can ease the child's discomfort. Painful genital blisters can be treated with an anesthetic cream recommended by a doctor or pharmacist. Antibiotics often are prescribed if blisters become infected.

Fever and discomfort can be reduced by acetaminophen or another medication that does not contain aspirin. Aspirin and any medications that contain aspirin or other salicylates must not be used with chickenpox, for they appear to increase the chances of developing Reye's syndrome. The best idea is to consult a doctor or pharmacist if unsure about which medications are safe.

Immunocompromised chickenpox sufferers are sometimes given an antiviral drug called acyclovir (Zovirax). Studies have shown that Zovirax also lessens the symptoms of otherwise healthy children and adults who contract chickenpox, but the suggestion that it should be used to treat the disease among the general population, especially in children, is controversial.

Alternative treatment

Alternative practitioners seek to lessen the discomfort and fever caused by chickenpox. Like other practitioners, they suggest cool or lukewarm baths. Rolled oats (Avena sativa ) in the bath water help relieve itching. (Oats should be placed in a sock, that is turned in the bath water to release the milky antiitch properties.) Other recommended remedies for itching include applying aloe vera, witch hazel, or herbal preparations of rosemary (Rosmarinus officinalis ) and calendula (Calendual officinalis ) to the blisters. Homeopathic remedies are selected on a case by case basis. Some common remedy choices are tartar emetic (antimonium tartaricum), windflower (pulsatilla), poison ivy (Rhus toxicodendron ), and sulphur.

Prognosis

Most cases of chickenpox run their course within a week without causing lasting harm. However, there is one long-term consequence of chickenpox that strikes about 20% of the population, particularly people 50 and older. Like all herpes viruses, the varicellazoster virus never leaves the body after an episode of chickenpox, but lies dormant in the nerve cells, where it may be reactivated years later by disease or age-related weakening of the immune system. The result is shingles (also called herpes zoster), a painful nerve inflammation, accompanied by a rash, that usually affects the trunk or the face for 10 days or more. Especially in the elderly, pain, called postherpetic neuralgia, may persist at the site of the shingles for months or years. Two relatively newer drugs for treatment of shingles have become available. Both valacy-clovir (Valtrex) and famciclovir (Famvir) stop the replication of herpes zoster when administered within 72 hours of appearance of the rash. The effectiveness of these two drugs in immunocompromised patients has not been established, and Famvir was not recommended for patients under 18 years.

Prevention

A substance known as varicella-zoster immune globulin (VZIG), which reduces the severity of chickenpox symptoms, is available to treat immunocompromised children and others at high risk of developing complications. It is administered by injection within 96 hours of known or suspected exposure to the disease and is not useful after that. VZIG is produced as a gamma globulin from blood of recently infected individuals.

KEY TERMS

Acetaminophen— A drug for relieving pain and fever. Tylenol is the most common example.

Acyclovir— An antiviral drug used for combating chickenpox and other herpes viruses. Sold under the name Zovirax.

Dehydration— Excessive water loss by the body.

Encephalitis— A disease that inflames the brain.

Hepatitis— A disease that inflames the liver.

Immune system— A biochemical complex that protects the body against pathogenic organisms and other foreign bodies.

Immunocompromised— Having a damaged immune system.

Pneumonia— A disease that inflames the lungs.

Pus— A thick yellowish or greenish fluid containing inflammatory cells. Usually caused by bacterial infection.

Reye's syndrome— A rare but often fatal disease that involves the brain, liver, and kidneys.

Salicylates— Substances containing salicylic acid, which are used for relieving pain and fever. Aspirin is the most common example.

Shingles— A disease (also called herpes zoster) that causes a rash and a very painful nerve inflammation. An attack of chickenpox will eventually give rise to shingles in about 20% of the population.

Trunk— That part of the body that does not include the head, arms, and legs.

Varicella-zoster immune globulin (VZIG)— A substance that can reduce the severity of chickenpox symptoms.

Varicella-zoster virus— The virus that causes chickenpox and shingles.

Varivax— A vaccine for the prevention of chickenpox.

Virus— A tiny particle that can cause infections by duplicating itself inside a cell using the cell's own software. Antibiotics are ineffective against viruses, though antiviral drugs exist for some viruses, including chickenpox.

A vaccine for chickenpox became available in the United States in 1995 under the name Varivax. Varivax is a live, attenuated (weakened) virus vaccine. It has been proven to be 85% effective for preventing all cases of chickenpox and close to 100% effective in preventing severe cases. Side effects are normally limited to occasional soreness or redness at the injection site. CDC guidelines state that the vaccine should be given to all children (with the exception of certain high-risk groups) at 12-18 months of age, preferably when they receive their measles-mumps-rubella vaccine. For older children, up to age 12, the CDC recommends vaccination when a reliable determination that the child in question has already had chickenpox cannot be made. Vaccination also is recommended for any older child or adult considered susceptible to the disease, particularly those, such as health care workers and women of childbearing age, who face a greater likelihood of severe illness or transmitting infection. A single dose of the vaccine was once thought sufficient for children up to age 12; older children and adults received a second dose four to eight weeks later. However, an outbreak at a daycare center in 2000 brought concern in the medical community about a second vaccination for younger children, since many of the affected children had been vaccinated. Researchers began recommending a second vaccination in 2002. In 1997 the cost of two adult doses of the vaccine in the United States was about $80. Although this cost was not always covered by health insurance plans, children up to age 18 without access to the appropriate coverage could be vaccinated free of charge through the federal Vaccines for Children program. Varivax is not given to patients who already have overt signs of the disease. It was once thought unsafe for children with chronic kidney disease, but a 2003 report said the vaccination was safe in these children. The finding is important, since even chickenpox can be a serious complication in children who must undergo a kidney transplant.

The vaccine also is not recommended for pregnant women, and women should delay pregnancy for three months following a complete vaccination. The vaccine is useful when given early after exposure to chickenpox and, if given in the midst of the incubation period, it can be preventative. The Infectious Diseases Society of America stated in 2000 that immunization is recommended for all adults who have never had chickenpox.

While there was initial concern regarding the vaccine's safety and effectiveness when first released, the vaccination is gaining acceptance as numerous states require it for admittance into daycare or public school. In 2000, 59% of toddlers in the United States were immunized; up from 43.2% in 1998. A study published in 2001 indicates that the varicella vaccine is highly effective when used in clinical practice. Although evidence has not ruled out a booster shot later in life, all research addressing the vaccine's effectiveness throughout its six-year use indicates that chickenpox may be the first human herpes virus to be wiped out. Although initial concerns questioned if the vaccination might make shingles more likely, studies are beginning to show the effectiveness of the vaccine in reducing cases of that disease.

Resources

PERIODICALS

Arvin, Ann M. "Varicella Vaccine-The First Six Years." New England Journal of Medicine March 2001.

"Chickenpox Vaccine OK for Pediatric Patients." Vaccine Weekly January 22, 2003: 25.

Henderson, C. W. "Chickenpox Immunization Confirmed Effective in Adults." Vaccine Weekly September 2000: 22.

"Study: Two Vaccines Work Best." Vaccine Weekly January 8, 2003: 14.

ORGANIZATIONS

Centers for Disease Control and Prevention. National Immunization Hotline. 1600 Clifton Rd. NE, Atlanta, GA 30333. (800) 232-2522 (English). (800) 232-0233 (Spanish). 〈http://www.cdc.gov〉.

OTHER

ABCNEWS.com. "Varicella Vaccine: States Mandate Chickenpox Immunization." August 1, 2000. [cited May 3, 2001]. 〈http://abcnews.go.com/sections/living/DailyNews/chickenpox_vaccine0802.html〉.

Centers for Disease Control and Prevention. "Prevention of Varicella: Recommendations of the Advisory Committee on Immunization Practices (ACIP)." July 12, 1996. [cited December 12, 1997]. 〈http://aepo-xdv-www.epo.cdc.gov/wonder/prevguid/m0042990/entire.htm〉.

Chickenpox

Symptoms of chickenpox

Treatment

Complications

Chickenpox and environmental factors

Immunity and vaccination

Resources

Chickenpox, a disease characterized by skin lesions and low-grade fever, is common in the United States and other countries located in areas with temperate climates. Until recently, the incidence of chickenpox was extremely high, and almost everyone living in the United States contracted chickenpox, usually during childhood. A chickenpox vaccine became available in 1995 and is now receiving widespread use. The annual case rate was reduced from about four million cases per year in the U.S to less than one million by the year 2000.

A highly contagious disease, chickenpox is caused by varicella-zoster virus (VZV), the same virus that causes the skin disease shingles. For most cases of chickenpox, no treatment besides pain relief and management of itching is necessary. In some cases, however, chickenpox may evolve into more serious conditions, such as bacterial infection of the skin lesions or pneumonia. These complications tend to occur in persons with weakened immune systems, such as children receiving chemotherapy for cancer or people with acquired immune deficiency syndrome (AIDS).

Despite its name, chickenpox has nothing to do with chickens. Its name has two possible origins. Some think that “chicken” comes from the French word chiche (chickpea) because at one stage of the disease, the lesions do indeed resemble chickpeas. Others think that “chicken” may have evolved from the Old English word gigan (to itch). Interestingly, the term “varicella” is a diminutive form of the term “variola,” the Latin term for smallpox. Although both chickenpox and smallpox are viral diseases that cause skin lesions, small-poxismoredeadlyanditslesions cause severe scarring.

Symptoms of chickenpox

Chickenpox is spread by breathing in respiratory droplets spread through the air by a cough or sneeze of an infected individual. Contact with the fluid from skin lesions can also spread the virus. The incubation period—or the time from exposure to VZV to the onset of the disease—is about 14-15 days. The most contagious period is just prior to the appearance of the rash, and early in the illness when fresh pox are still appearing. The first sign of chickenpox in children is often the appearance of the chickenpox rash. Adults and some children may have a prodrome, or series of warning symptoms. This precursor is typical of the flu, and includes headache, fatigue, backache, and a fever. The onset of the rash is quite rapid. First, small red “dots” appear on the skin. Soon, a vesicle containing clear fluid appears in the center of the dot. This small, reddish bump with a central clear fluid is sometimes referred to as “dewdrop on a rose petal” appearance. The vesicle rapidly dries, forming a crust. This cycle, from the appearance of the dot to the formation of the crust, can take place within eight to 12 hours. As the crust dries, it falls off, leaving a slight depression that eventually recedes.

Over the course of a case of chickenpox, an individual may develop between 250 and 500 skin lesions. The lesions occur in waves, with the first set of lesions drying up just as successive waves appear. The waves appear over two to four days. The entire disease runs its course in about a week, but the lesions continue to heal for about two to three weeks. The lesions first appear on the scalp and trunk. Most of the lesions in chickenpox are found at the center of the body; few lesions form on the soles and palms. Lesions are also found on the mucous membranes, such as the respiratory tract, the gastrointestinal tract, and the urogenital tract. Researchers think that the lesions on the respiratory tract may help transmit the disease. If a person with respiratory lesions coughs, they may spray some of the vesicle fluid into the atmosphere to be breathed by other susceptible persons.

Although the lesions look serious, chickenpox in children is usually a mild disease with few complications and a low fever. Occasionally, if the rash is severe, the fever may be higher. Chickenpox is more serious in adults, who usually have a higher fever and general malaise. It can cause damage to the eyes and, in males, the testes. An adult with chickenpox also requires a longer period of recuperation than does a child. The most common complaint about chickenpox from both children and adults is the itching caused by the lesions. Though scarring from chickenpox is rare, it is important not to scratch the lesions, as scratching may cause scarring.

Treatment

Because chickenpox is usually a mild disease, no drug treatment is prescribed. Pain relief, in the form of acetaminophen (i.e., Tylenol) is recommended rather than salicylate, or aspirin. Salicylate may cause Reye’s syndrome, a very serious neurological condition that is especially associated with aspirin intake and chickenpox; in fact, 20-30% of the total cases of Reye’s syndrome occur in children with chickenpox. It is therefore important to control pain in children with chickenpox (or any other respiratory illness) with acetaminophen, not aspirin. Adults should also take acetaminophen if they have chickenpox.

The itching of the lesions can sometimes be controlled with calamine lotion or special preparations that are put into bath water. Antihistamines may also help relieve itching. The itching becomes less severe as the lesions heal; however, because children are more likely to scratch the lesions, the potential for scarring is greater in children than in adults.

Chickenpox, although not deadly for most people, can be quite serious in those who have weakened immune systems, and drug therapy is recommended for these cases. Antiviral drugs (such as acyclovir) have been shown to lessen the severity and duration of the disease, although some of the side effects, such as gastrointestinal upset, can be problematic.

Complications

If the lesions are severe and the person has scratched them, bacterial infection of the lesions can result. This complication is managed with antibiotic treatment. A more serious complication is pneumonia. Pneumonia is rare in otherwise healthy children and is more often seen in older patients or in children who already have a serious disease, such as cancer. Pneumonia is also treated with antibiotics. Another complication of chickenpox is shingles. Shingles are painful outbreaks of skin lesions that occur some years after a bout with chickenpox. Shingles are caused by VZV left behind in the body, which then becomes reactivated. Shingles causes skin lesions and burning pain along the region served by a specific nerve. It is not clear why VZV is reactivated in some people and not in others, but many people with compromised immune systems can develop severe, even life-threatening cases of shingles.

Pregnant women are more susceptible to chickenpox, which also poses a threat to both prenatal and newborn children. If a woman contracts chickenpox in the first trimester (first three months) of pregnancy, the fetus may be at increased risk for birth defects such as scarring and eye damage. A newborn may contract chickenpox in the uterus if the mother has chickenpox five days before birth. Newborns can also contract chickenpox if the mother has the disease up to two days after birth. Chickenpox can be a deadly disease for newborns—the fatality rate from chickenpox in newborns up to five days old is about 30%. For this reason, women contemplating pregnancy may opt to

KEY TERMS

Immunocompromised— A condition in which the immune system is weakened, as during chemotherapy for cancer or infection with AIDS.

Reye’s syndrome— A neurological condition that usually occurs in children; associated with a respiratory illness and aspirin intake.

be vaccinated with the new VZV vaccine prior to conception if they have never had the disease. If this has not been done and a pregnant woman contracts chick-enpox, an injection of varicella-zoster immunoglobulin can lessen the chance of complications to the fet us.

Chickenpox and environmental factors

Researchers have long noted the seasonality of chickenpox. According to their research, chickenpox cases occur at their lowest rate during September. Numbers of cases increase throughout the autumn, peak in March and April, and then fall sharply once summer begins. This cycle corresponds to the typical school year in the United States. When children go back to school in the fall, they begin to spread the disease; when summer comes and school ends, cases of chick-enpox diminish. A typical “mini-epidemic” within a school occurs when one child contracts chickenpox. This child rapidly infects other susceptible children. Soon, all the children who had not had chickenpox contract the disease within two or three cycles of transmission. It is not uncommon for high numbers of children to be infected during one “mini-epidemic.”

Immunity and vaccination

Contrary to popular belief, it is possible to get chickenpox a second time. If a person had a mild case during childhood, his or her immunity to the virus may be weaker than that of someone who had a severe childhood case. In order to prevent chickenpox, especially in already-ill children and immunocompromised patients, the VZV vaccine, consisting of live, attenuated (modified) VZV is used. Immunization recommendations of the American Academy of Pediatrics state that children between 12 and 18 months of age who have not yet had chickenpox should receive the vaccine. Immunization can be accomplished with a single dose. Children up to the age of 13 who have had neither chickenpox nor the immunization should also receive a single dose of the vaccine. Children older than age 13 who have never had either chickenpox or the vaccine should be immunized with two separate doses, given about a month apart. The vaccine provokes strong immunity against the virus. Although some side effects have been noted, including a mild rash and the reactivation of shingles, the vaccine is considered safe and effective.

See also Childhood diseases.

Resources

PERIODICALS

Malhotra, R. “Nasolacrimal Duct Obstruction Following Chicken Pox.” Eye 16, no. 1 (2002): 88-89.

Ortolon, Ken. “Short On Shots.” Texas Medicine 98, no. 5 (2002): 30-33.

“Varicella Seroprevalence In A Random Sample Of The Turkish Population.” Vaccine 20, Issue: no. 10 (2002): 1425-1428.

OTHER

Centers for Disease Control and Prevention. “Varicella Disease (Chickenpox)” <http://www.cdc.gov/nip/diseases/varicella/>(accessed November 21, 2006).

MayoClinic.com “Chickenpox” <http://www.mayoclinic.com/health/chickenpox/DS00053>(accessed November 25, 2006).

Kathleen Scogna

Chickenpox

Definition

Chickenpox (also called varicella) is a common, extremely infectious, rash-producing childhood disease that also affects adults on occasion.

Description

Chickenpox is caused by the varicella-zoster virus (a member of the herpes virus family), which is spread through the air or by direct contact with an infected person. It produces an itchy, blistery rash that typically lasts about a week and is sometimes accompanied by a fever or other symptoms. A single attack of chickenpox almost always brings lifelong immunity against the disease. Because the symptoms of chickenpox are easily recognized and in most cases merely unpleasant rather than dangerous, treatment can almost always be carried out at home. Severe complications can develop, however, and professional medical attention is essential in some circumstances.

Once someone has been infected with the virus, an incubation period of about 10 to 21 days passes before symptoms begin. The period during which infected people are able to spread the disease is believed to start one or two days before the rash breaks out and to continue until all the blisters have formed scabs, which usually happens four to seven days after the rash breaks out but may be longer in adolescents and adults. For this reason, doctors recommend keeping children with chickenpox away from school for about a week. It is not necessary, however, to wait until all the scabs have fallen off.

Prior to the use of the varicella vaccine, chickenpox was a typical part of growing up for most children in the industrialized world. The disease can strike at any age, but throughout the twentieth century by ages nine or ten about 80 to 90 percent of American children had already been infected. U.S. children living in rural areas and many foreign-born children were less likely to be immune. Study results reported by the Centers for Disease Control and Prevention (CDC) indicate that more than 90 percent of American adults are immune to the chickenpox virus. Adults, however, are much more likely than children to suffer dangerous complications. More than half of all chickenpox deaths occur among adults.

Demographics

Before the varicella vaccine (Varivax) was released for use in 1995, nearly all of the 4 million children born each year in the United States contracted chickenpox, resulting in hospitalization in five of every 1,000 cases and 100 deaths. Because almost every case of chickenpox, no matter how mild, leads to lifelong protection against further attacks, adults account for less than 5 percent of all cases in the United States.

Causes and symptoms

A case of chickenpox usually starts without warning or with only a mild fever and a slight feeling of unwellness. Within a few hours or days small red spots begin to appear on the scalp, neck, or upper half of the trunk. After another 12 to 24 hours the spots typically become itchy, fluid-filled bumps called vesicles, which continue to appear in crops for the next two to five days. In any area of skin, lesions of a variety of stages can be seen. These blisters can spread to cover much of the skin, and in some cases also may be found inside the mouth, nose, ears, vagina, or rectum. Some people develop only a few blisters, but in most cases the number reaches 250 to 500. The blisters soon begin to form scabs and fall off. Scarring usually does not occur unless the blisters have been scratched and become infected. Occasionally a minor and temporary darkening of the skin (called hyperpigmentation) is noticed around some of the blisters. The degree of itchiness can range from barely noticeable to extreme. Some chickenpox sufferers also have headaches, abdominal pain , or a fever. Full recovery usually takes five to ten days after the first symptoms appear. Again, the most severe cases of the disease tend to be found among older children and adults.

Although for most people chickenpox is no more than a matter of a few days' discomfort, some groups are at risk for developing complications, the most common of which are bacterial infections of the blisters, pneumonia, dehydration, encephalitis , and hepatitis. Some of the groups at greater risk are:

• Infants: Complications occur much more often among children younger than one year old than among older children. The threat is greatest to newborns, who are more at risk of death from chickenpox than any other group. Under certain circumstances, children born to mothers who contract chickenpox just prior to delivery face an increased possibility of dangerous consequences, including brain damage and death. If the infection occurs during early pregnancy, there is a small (less than 5%) risk of congenital abnormalities.
• Immunocompromised children: Children whose immune systems have been weakened by a genetic disorder, disease, or medical treatment usually experience the most severe symptoms of any group. They have the second-highest rate of death from chickenpox.
• Adults and children 15 and older: Among this group, the typical symptoms of chickenpox tend to strike with greater force, and the risk of complications is much higher than among young children.

Immediate medical help should always be sought when anyone in these high-risk groups contracts the disease.

Diagnosis

Where children are concerned, especially those with recent exposure to the disease, diagnosis can usually be made at home, by a school nurse, or by a doctor over the telephone if the child's parent or caregiver is unsure that the disease is chickenpox.

Treatment

With children, treatment usually takes place in the home and focuses on reducing discomfort and fever. Because chickenpox is a viral disease, antibiotics are ineffective against it.

Applying wet compresses or bathing the child in cool or lukewarm water once a day can help the itch. Adding four to eight ounces of baking soda or one or two cups of oatmeal to the bath is a good idea (oatmeal bath packets are sold by pharmacies). Only mild soap should be used in the bath. Patting, not rubbing, is recommended for drying the child off, to prevent irritating the blisters. Calamine lotion (and some other kinds of lotions) also reduces itchiness. Because scratching can cause blisters to become infected and lead to scarring, the child's nails should be cut short. Of course, older children need to be warned not to scratch. For babies, light mittens or socks on the hands can help guard against scratching.

If mouth blisters make eating or drinking an unpleasant experience, cold drinks and soft, bland foods can ease the child's discomfort. Painful genital blisters can be treated with an anesthetic cream recommended by a doctor or pharmacist. Antibiotics often are prescribed if blisters become infected.

Fever and discomfort can be reduced by acetaminophen or another medication that does not contain aspirin. Aspirin and any medications that contain aspirin or other salicylates must not be used with chickenpox, for they appear to increase the chances of developing Reye's syndrome . The best idea is for a parent to consult a doctor or pharmacist to confirm which medications are safe.

Immunocompromised chickenpox sufferers are sometimes given an antiviral drug called acyclovir (Zovirax). Studies have shown that Zovirax also lessens the symptoms of otherwise healthy children and adults who contract chickenpox, but the notion that it should be used to treat the disease among the general population, especially in children, is controversial.

Prognosis

Most cases of chickenpox run their course within a week without causing lasting harm. However, there is one long-term consequence of chickenpox that strikes about 20 percent of the population, particularly people 50 and older. Like all herpes viruses, the varicella-zoster virus never leaves the body after an episode of chickenpox. It lies dormant in the nerve cells, where it may be reactivated years later by disease or age-related weakening of the immune system. The result is shingles (also called herpes zoster), a painful nerve inflammation, accompanied by a rash that usually affects the trunk or the face for ten days or more. Especially in the elderly, pain, called postherpetic neuralgia, may persist at the site of the shingles for months or years. As of 2004, two relatively newer drugs for treatment of shingles are valacyclovir (Valtrex) and famciclovir (Famvir), both of which stop the replication of herpes zoster when administered within 72 hours of appearance of the rash. The effectiveness of these two drugs in immunocompromised patients has not been established, and Famvir was not recommended for patients under 18 years.

Prevention

A substance known as varicella-zoster immune globulin (VZIG), which reduces the severity of chickenpox symptoms, is as of 2004 available to treat immunocompromised children and others at high risk of developing complications. It is administered by injection within 96 hours of known or suspected exposure to the disease and is not useful after that. VZIG is produced as a gamma globulin from blood of recently infected individuals.

A vaccine for chickenpox became available in the United States in 1995 under the name Varivax. Varivax is a live, attenuated (weakened) virus vaccine. It has been proven to be 85 percent effective for preventing all cases of chickenpox and close to 100 percent effective in preventing severe cases. Side effects are normally limited to occasional soreness or redness at the injection site. CDC guidelines state that the vaccine should be given to all children (with the exception of certain high-risk groups) at 12 to 18 months of age, preferably when they receive their measles-mumps-rubella vaccine. For older children, up to age 12, the CDC recommends vaccination when a reliable determination that the child in question has already had chickenpox cannot be made. Vaccination also is recommended for any older child or adult considered susceptible to the disease, particularly those, such as healthcare workers and women of childbearing age, who face a greater likelihood of severe illness or transmitting infection. A single dose of the vaccine was once thought sufficient for children up to age 12; older children and adults received a second dose four to eight weeks later. However, an outbreak at a daycare center in 2000 brought concern in the medical community about a second vaccination for younger children, since many of the affected children had been vaccinated. Researchers began recommending a second vaccination in 2002. In 1997, the cost of two adult doses of the vaccine in the United States was about $80. Although this cost was not always covered by health insurance plans, children up to age 18 without access to the appropriate coverage could be vaccinated free of charge through the federal Vaccines for Children program. Varivax is not given to patients who already have overt signs of the disease. It was once thought unsafe for children with chronic kidney disease, but a 2003 report said the vaccination was safe in these children. The finding is important, since even chickenpox can be a serious complication in children who must undergo a kidney transplant.

The vaccine also is not recommended for pregnant women, and women should delay pregnancy for three months following a complete vaccination. The vaccine is useful when given early after exposure to chickenpox and, if given in the midst of the incubation period, it can be preventative. The Infectious Diseases Society of America stated in 2000 that immunization is recommended for all adults who have never had chickenpox.

KEY TERMS

Acetaminophen —A drug used for pain relief as well as to decrease fever. A common trade name for the drug is Tylenol.

Acyclovir —An antiviral drug, available under the trade name Zovirax, used for combating chickenpox and other herpes viruses.

Dehydration —An excessive loss of water from the body. It may follow vomiting, prolonged diarrhea, or excessive sweating.

Encephalitis —Inflammation of the brain, usually caused by a virus. The inflammation may interfere with normal brain function and may cause seizures, sleepiness, confusion, personality changes, weakness in one or more parts of the body, and even coma.

Hepatitis —An inflammation of the liver, with accompanying liver cell damage or cell death, caused most frequently by viral infection, but also by certain drugs, chemicals, or poisons. May be either acute (of limited duration) or chronic (continuing). Symptoms include jaundice, nausea, vomiting, loss of appetite, tenderness in the right upper abdomen, aching muscles, and joint pain. In severe cases, liver failure may result.

Immune system —The system of specialized organs, lymph nodes, and blood cells throughout the body that work together to defend the body against foreign invaders (bacteria, viruses, fungi, etc.).

Immunocompromised —A state in which the immune system is suppressed or not functioning properly.

Pneumonia —An infection in which the lungs become inflamed. It can be caused by nearly any class of organism known to cause human infections, including bacteria, viruses, fungi, and parasites.

Pus —A thick, yellowish or greenish fluid composed of the remains of dead white blood cells, pathogens, and decomposed cellular debris. It is most often associated with bacterial infection.

Reye's syndrome —A serious, life-threatening illness in children, usually developing after a bout of flu or chickenpox, and often associated with the use of aspirin. Symptoms include uncontrollable vomiting, often with lethargy, memory loss, disorientation, or delirium. Swelling of the brain may cause seizures, coma, and in severe cases, death.

Salicylates —A group of drugs that includes aspirin and related compounds. Salicylates are used to relieve pain, reduce inflammation, and lower fever.

Shingles —An disease caused by an infection with the Herpes zoster virus, the same virus that causes chickenpox. Symptoms of shingles include pain and blisters along one nerve, usually on the face, chest, stomach, or back.

Trunk —That part of the body that does not include the head, arms, and legs. Also called the torso.

Varicella zoster —The virus that causes chickenpox (varicella).

Varicella-zoster immune globulin —A substance that can reduce the severity of chickenpox symptoms.

Varivax —The brand name for varicella virus vaccine live, an immunizing agent used to prevent infection by the Herpes (Varicella) zoster virus. The vaccine works by causing the body to produce its own protection (antibodies) against the virus.

Virus —A small infectious agent consisting of a core of genetic material (DNA or RNA) surrounded by a shell of protein. A virus needs a living cell to reproduce.

While there was initial concern regarding the vaccine's safety and effectiveness when first released, the vaccination is in the early 2000s gaining acceptance as numerous states require it for admittance into daycare or public school. In 2000, 59 percent of toddlers in the United States were immunized; up from 43.2 percent in 1998. A study published in 2001 indicates that the varicella vaccine is highly effective when used in clinical practice. Although evidence has not ruled out a booster shot later in life, all research addressing the vaccine's effectiveness throughout its six-year use indicates that chickenpox may be the first human herpes virus to be wiped out. Although initial concerns questioned if the vaccination might make shingles more likely, studies are beginning in the early 2000s to show the effectiveness of the vaccine in reducing cases of that disease.

Parental concerns

A doctor should be called immediately if any of the following occur:

• The child's fever goes above 102°F (38.9°C) or takes more than four days to disappear.
• The child's blisters appear infected. Signs of infection include leakage of pus from the blisters or excessive redness, warmth, tenderness, or swelling around the blisters.
• The child seems nervous, confused, unresponsive, or unusually sleepy; complains of a stiff neck or severe headache ; shows signs of poor balance or has trouble walking; finds bright lights hard to look at; is having breathing problems or is coughing a lot; is complaining of chest pain; is vomiting repeatedly; or is having convulsions. These may be signs of Reye's syndrome or encephalitis, two rare but potentially dangerous conditions.

Resources

BOOKS

Arvin, Ann M. "Varicella-zoster Virus." In Principles and Practice of Pediatric Infectious Diseases, 2nd ed. Edited by Sarah S. Long et al. St. Louis, MO: Elsevier, 2003.

Myers, Martin G., et al. "Varicella-Zoster Virus." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.

PERIODICALS

Arvin, Ann M. "Varicella Vaccine: The First Six Years." New England Journal of Medicine (March 2001).

"Chickenpox Vaccine OK for Pediatric Patients." Vaccine Weekly (January 22, 2003): 25.

Henderson, C. W. "Chickenpox Immunization Confirmed Effective in Adults." Vaccine Weekly (September 2000): 22.

"Study: Two Vaccines Work Best." Vaccine Weekly (January 8, 2003): 14.

ORGANIZATIONS

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. Web site: <www.cdc.gov>.

WEB SITES

"Chickenpox." MedlinePlus. Available online at <www.nlm.nih.gov/medlineplus/chickenpox.html> (accessed December 25, 2004).

Beth A. Kapes Teresa G. Odle Rosalyn Carson-DeWitt, MD

Chickenpox

Definition

Chickenpox (varicella) is a common and extremely infectious childhood disease that also occasionally affects adults. It produces an itchy, blistery rash that typically lasts about a week and is sometimes accompanied by a fever or other symptoms.

Description

About four million Americans contract chickenpox each year, resulting in roughly 5,000-9,000 hospitalizations and 100 deaths. Chickenpox is caused by the varicella-zoster virus (a member of the herpes virus family), which is spread through the air or by direct contact with an infected person. Once someone has been infected with the virus, symptoms appear in about 10-21 days. The period during which infected people can spread the disease is believed to start one or two days before the rash appears until all the blisters have formed scabs, usually four to seven days after the rash breaks out. For this reason, doctors recommend keeping children with chickenpox away from school for about a week.

Chickenpox has been a typical part of growing up for most children in the industrialized world (although this may change because of the new varicella vaccine). The disease can strike at any age, but by ages nine or 10 about 80-90% of American children have already been infected. U.S. children living in rural areas and many foreign-born children are less likely to be immune. Because almost every case of chickenpox leads to lifelong protection, adults account for less than 5% of all cases in the United States. Study results reported by the Centers for Disease Control and Prevention (CDC) indicate that more than 90% of American adults are immune to the chickenpox virus. Adults, however, are much more likely than children to suffer dangerous complications. More than half of all chickenpox deaths occur among adults.

Causes & symptoms

A case of chickenpox usually starts without warning or with only a mild fever and a slight feeling of unwellness. Within a few hours or days small red spots begin to appear on the scalp, neck, or upper half of the trunk. After a further 12-24 hours the spots typically become itchy, fluid-filled bumps called vesicles, which continue to appear for the next two to five days. In any area of skin, lesions of a variety of stages can be seen. These blisters can spread to cover much of the skin, and in some cases may also be found inside the mouth, nose, ears, vagina, or rectum. Some people develop only a few blisters, but in most cases the number reaches 250-500. The blisters soon begin to form scabs and fall off. Scarring usually does not occur unless the blisters have been scratched and become infected. Occasionally a minor and temporary darkening of the skin (called hyperpigmentation) is noticed around some of the blisters. The degree of itchiness can range from barely noticeable to extreme. Some chickenpox sufferers also have headaches, abdominal pain , or a fever. Full recovery usually takes five to 10 days after the first symptoms appear. The most severe cases of the disease tend to be found among older children and adults.

Some groups are at risk for developing complications, the most common of which are bacterial infections of the blisters, pneumonia , dehydration, encephalitis, and hepatitis . Immediate medical help should always be sought when anyone in these high-risk groups contracts the disease. These include:

• Infants. Complications occur much more often among children less than one year old than among older children. The threat is greatest to newborns, who are more at risk of death from chickenpox than any other group. Children born to mothers who contract chickenpox just prior to delivery face an increased possibility of dangerous consequences, including brain damage and death. If the infection occurs during early pregnancy , there is a small (less than 5%) risk of birth defects.
• Immunocompromised children. Children whose immune systems have been weakened by a genetic disorder, disease, or medical treatment usually experience the most severe symptoms of any group. They have the second-highest rate of death from chickenpox.
• Adults and children 15 and older. The typical symptoms of chickenpox tend to strike this group with greater force.

Diagnosis

Where children are concerned, especially those with recent exposure to the disease, diagnosis can usually be made at home, by a school nurse, or by a doctor over the telephone if the child's parent or caregiver is unsure that the disease is chickenpox. A doctor should be called immediately if:

• The child's fever goes above 102°F (38.9°C) or takes more than four days to disappear.
• The child's blisters appear infected. Signs of infection include pus drainage or excessive redness, warmth, tenderness, or swelling.
• The child seems nervous, confused, unresponsive, or unusually sleepy; complains of a stiff neck or severe headache ; shows signs of poor balance or has trouble walking; finds bright lights hard to look at; is having breathing problems or is coughing a lot; is complaining of chest pain; is vomiting repeatedly; or is having convulsions. These may be signs of Reye's syndrome or encephalitis, two rare but potentially very dangerous conditions.

Treatment

Treatment focuses on reducing symptoms of chickenpox. The patient should drink plenty of fluids and eat simple, nutritious foods. Soups (especially mung bean), herbal teas, and fruit juices are good choices.

Applying wet compresses or bathing the patient in cool or lukewarm water once a day can help the itch.

Adding four to eight ounces of baking soda or one or two cups of oatmeal to the bath is helpful. Only mild soap should be used and patting, not rubbing, is recommended for drying the patient. The patient should not scratch the blisters as this can lead to infection or scarring. For babies, light mittens or socks on the hands can help guard against scratching. If mouth blisters are present, cold drinks and soft, bland foods can make eating less painful.

Supplements

Vitamin A may help to heal skin. Vitamin C and bioflavinoids help to reduce fever and stimulate the immune system. Zinc stimulates the immune system and promotes healing. Zinc can cause nausea and vomiting. Calcium and magnesium help to relieve restlessness and sleeping difficulties. Magnesium has a laxative effect at high doses.

Herbals and Chinese medicine

The following herbals are ingested to treat chickenpox:

• Echinacea and goldenseal (Hydrastis canadensis ) support the immune system, and soothe skin and mucous membranes. Echinacea is also an antiviral.
• Chamomile tea is a sleep aid.
• Chinese cucumber (Trichosanthes kirilowii ) root tea is used to relieve symptoms of chickenpox.
• Elder flower, peppermint , and yarrow reduce fever.
• Garlic has antiviral activity.
• Mullein (Verbascum thapsus ) treats chickenpox.
• Yin Qiao Jie Du Wan (Honeysuckle and Forsythia Pill).
• Ban Lan Gen Chong Ji (Isatis Infusion).

The following herbals are used externally to treat chickenpox:

• Aloe leaf, calendula , and plantain relieve the itching of the chickenpox rash.
• Turmeric powder mixed with lime juice treats chickenpox rash.
• Garlic clears skin infection.

Other remedies

Homeopathic remedies are selected on a case by case basis. Some common remedy choices are apis , aconitum, belladonna , calendula, antimonium tartaricum, pulsatilla, Rhus toxicodendron, and sulphur.

The acupressure points Four Gates, Large Intestine 11, Spleen 10, and Stomach 36 help alleviate symptoms associated with chickenpox.

Allopathic treatment

Treatment usually focuses on reducing discomfort and fever. Because chickenpox is a viral disease, antibiotics are ineffective. Antibiotics may be prescribed if the blisters become infected. Calamine lotion helps to reduce itchiness. Painful genital blisters can be treated with an anesthetic cream recommended by a doctor or pharmacist.

Fever and discomfort can be reduced by acetaminophen (Tylenol) or other medications that do not contain aspirin. Aspirin (or any aspirin-containing medications) must not be used with chickenpox, because it increases the chances of developing Reye's syndrome. The best idea is to consult a doctor or pharmacist if one is unsure about which medications are safe.

Immunocompromised chickenpox sufferers are sometimes given the antiviral drug acyclovir (Zovirax). Zovirax also lessens the symptoms of chickenpox in otherwise healthy children and adults.

Expected results

Most cases of chickenpox run their course within a week. The varicella-zoster virus lies dormant in the nerve cells, where it may be reactivated years later by disease or age-related weakening of the immune system. The result is shingles (herpes zoster), a very painful rash and nerve inflammation, that strikes about 20% of the population, particularly people 50 and older.

Prevention

A substance known as varicella-zoster immune globulin (VZIG), which reduces the severity of chickenpox symptoms, is available to treat persons at high risk of developing complications. It is administered by injection within 96 hours of known or suspected exposure to the disease.

A vaccine for chickenpox (Varivax) has been found to prevent the disease in 70-90% of the vaccinated population, to reduce the severity of disease in the remaining cases. CDC and the American Academy of Pediatricians recommend vaccination of all children (with some exceptions) at 12-18 months of age. For older children, up to age 12, the CDC recommends vaccination when immunity cannot be confirmed. Vaccination is also recommended for any older child or adult considered susceptible to the disease, particularly those who face a greater likelihood of severe illness or transmitting infection. A single dose of the vaccine is sufficient for children up to age 12; older children and adults receive a second dose four to eight weeks later.

Resources

BOOKS

Pattishall, Evan G., III. "Chickenpox." In Primary Pediatric Care. edited by Robert A. Hoekelman, et al. St. Louis: Mosby, 1997.

Ying, Zhou Zhong, and Jin Hui De. "Common Diseases of Pediatrics." In Clinical Manual of Chinese Herbal Medicine and Acupuncture. New York: Churchill Livingston, 1997.

PERIODICALS

Kump, Theresa. "Childhood Without Chickenpox? Why Parents Are Still Wary of This New Vaccine." Parents. (April 1996): 39-40.

Napoli, Maryann. "The Chickenpox Vaccine." Mothering. (Summer 1996): 56-61.

Shapiro, Eugene D., and Phillip S. LaRussa. "Vaccination for Varicella—Just Do It!" Journal of the American Medical Association 278 (1997): 1529-1530.

ORGANIZATIONS

Centers for Disease Control and Prevention. National Immunization Hotline. 1600 Clifton Rd. NE, Atlanta, GA 30333. (800) 232-2522 (English). (800) 232-0233 (Spanish). http://www.cdc.gov.

OTHER

Centers for Disease Control and Prevention." Prevention of Varicella: Recommendations of the Advisory Committee on Immunization Practices (ACIP)." http://aepo-xdvwww.epo.cdc.gov/wonder/prevguid/m0042990/entire.htm (12 December 1997).

Zand, Janet. "Chickenpox." HealthWorld Online. http://www.healthy.net/library/books/smart/chcknpox.htm.

Belinda Rowland

CHICKENPOX

DEFINITION

Chickenpox, also called varicella (pronounced VAR-ih-SEL-uh), is a common and very infectious childhood disease, which sometimes affects adults. Chickenpox produces an itchy rash with blisters that lasts about a week. Fever and other symptoms may also be present. A single attack of chickenpox generally produces lifelong immunity (protection) against the disease, which means once you have chickenpox you usually never have it again.

Chickenpox can almost always be treated at home. The symptoms are unpleasant, but they are rarely dangerous. If complications develop, professional medical attention is essential.

DESCRIPTION

Chickenpox is caused by the varicella-zoster virus (a herpes virus; see herpes infections entry) and affects about four million Americans each year. Of this number, five thousand to nine thousand require hospitalization. About one hundred people die of the disease each year.

A person becomes infectious (able to pass on the virus) a day or two before a rash first appears. He or she remains infectious until the blisters have formed scabs. Scabs form four to seven days after the rash first appears. During this period, a child with chickenpox is expected to stay home from school so that he or she will not pass the disease to other children.

Chickenpox has always been a common disease among children in the industrialized world. The disease can occur at any age. However, about 80 to 90 percent of all American children under the age of ten have already been infected. Because a single attack of the virus provides immunity, chickenpox occurs in only 5 percent of adults in the United States. If an adult contracts chickenpox he or she is more likely to experience complications than children; more than half of all deaths from chickenpox occur among adults.

CAUSES

Chickenpox is caused by a virus that is transmitted through the air or by direct contact with an infected person. Once the virus enters a person's body, there is an incubation period of ten to twenty-one days. During this period, the virus reproduces and grows in the body, but no symptoms appear.

SYMPTOMS

The first signs of chickenpox are usually a slight fever and a general feeling of illness. Within a few hours or days, small red spots begin to appear on the scalp, neck, or upper half of the body. About twelve to twenty-four hours later, these spots become itchy and develop into fluid-filled bumps. These bumps, called vesicles, go through a series of changes. First they turn into blisters. Then they break open, and scabs begin to form on top of them. This process goes on for a period of two to five days.

Blisters can also form on other parts of the body, including the insides of the mouth, nose, ears, vagina, and rectum. Some people develop only a few blisters. In most cases, however, the number reaches 250 to 500. Toward the end of the disease, scabs begin to fall off. Scarring normally does not occur unless the blisters are scratched and become infected.

Chickenpox: Words to Know

Acetaminophen:

A drug for relieving pain and fever. Tylenol is the most common example.

Acyclovir:

An antiviral drug used for combating chickenpox and other herpes viruses.

Reye's syndrome:

A rare but often fatal disease that involves the brain, liver, and kidneys.

Shingles:

A disease that causes a rash and a very painful nerve inflammation. An attack of chickenpox eventually gives rise to shingles in about 20 percent of the population.

Varicella-zoster immune globulin (VZIG):

A substance that can reduce the severity of chickenpox symptoms.

Varicella-zoster virus:

The virus that causes chickenpox and shingles.

Varivax:

A vaccine for the prevention of chickenpox.

The amount of itchiness caused by the blisters can range from barely noticeable to severe. People with chickenpox may also have headaches, stomach pain, and a fever. Full recovery usually takes five to ten days after symptoms first appear. Again, the most severe cases of the disease are usually found among older children and adults.

Some groups of people are at risk for developing complications in connection with chickenpox. The most common of these complications are bacterial infections of the blisters, pneumonia (see pneumonia entry), dehydration (loss of water from the body), encephalitis (brain fever; see encephalitis entry), and hepatitis (inflammation of the liver; see hepatitis entry). The groups at risk for these complications include:

• Infants. Complications occur more often among children less than one year old than among older children. The risk is greatest to newborns, among whom the death rate is greater than for any other age group. Babies are especially at risk when born to women who had chickenpox while they were pregnant. In such cases, the child faces the risk of physical disorders, brain damage, or death.
• Children with damaged immune systems. A child's immune system can be damaged by many factors, including genetic disorders or disease. Children in this group have the second highest death rate from chickenpox.
• Adults and children over the age of 15. Chickenpox is generally more serious in these age groups than it is among younger children.

DIAGNOSIS

It is usually quite easy to diagnose chickenpox in children. A school nurse or a parent is often able to recognize the disease. A doctor can sometimes diagnose the disease over the telephone. The doctor should also be called if:

• The child's fever goes above 102°F (39°C) or lasts more than four days.
• The child's blisters appear to be infected. Signs of infection include leakage of pus from blisters, or excessive redness, warmth, tenderness, or swelling around the blisters.
• The child seems nervous, confused, unresponsive, or unusually sleepy. A stiff neck or severe headache, poor balance or trouble walking, sensitivity to bright lights, breathing problems or excessive coughing, and chest pain or vomiting could be signs of more serious illnesses, such as Reye's syndrome (see Reye's syndrome entry) or encephalitis.

TREATMENT

With children, treatment of chickenpox usually takes place in the home and focuses on reducing fever and discomfort. Because chickenpox is caused by a virus, antibiotics are not effective against the disease. Applying wet compresses (folded cloths) can help relieve itching. Cool or lukewarm baths once a day may also help. The addition of baking soda or oatmeal to the bath water makes the bath more soothing. Only mild soaps should be used for the bath. The child should be patted dry, not rubbed, to prevent irritating the blisters. Calamine lotion also helps to reduce itching.

The child's fingernails should be kept short during the disease. That will prevent scratching of the blisters, which can lead to infection. Older children should be warned not to scratch. For babies, light mittens or socks on the hands can help guard against scratching.

Blisters in the mouth can make eating and drinking uncomfortable. Children may find it easier to have cold drinks and soft, bland foods. Genital blisters can be treated with an anesthetic (pain-killing) cream recommended by a doctor or pharmacist. Antibiotics are used if blisters become infected.

Acetaminophen (pronounced uh-see-tuh-MIN-uh-fuhn) and other drugs can be used to treat fever and discomfort. Aspirin should be avoided when treating children. It has been shown to cause Reye's syndrome in children, a serious disease of the nervous system.

Children with weakened immune systems may be given antiviral (viruskilling) drugs, such as acyclovir (pronounced a-SI-klo-veer, trade name Zovirax). The drug has been recommended by some doctors for the relief of chickenpox symptoms in children and adults with normal immune systems, but experts still disagree about the use of acyclovir for this purpose.

Alternative Treatment

Along with cool or lukewarm baths, alternative practitioners recommend the use of various natural products, such as aloe vera, witch hazel, or a combination of rosemary and calendula, for treating itching caused by blisters. Some common homeopathic remedies include windflower, poison ivy, and sulfur.

PROGNOSIS

Most cases of chickenpox last about a week without causing lasting harm. One long-term effect of chickenpox is seen in about 20 percent of the population, however. This effect occurs most often in people over the age of fifty, and is the disease known as shingles. Shingles is caused by the same virus that causes chickenpox. After a chickenpox infection has disappeared, the virus may remain in a person's body. At some time later in life, the virus may once again become active. It produces a new form of infection—shingles.

Shingles is a very painful inflammation of the nerves caused by the chickenpox virus. It is accompanied by a rash that covers the trunk of the body (the part of the body that does not include the arms, legs, or head) and the face for ten days or more. In some cases, the pain caused by shingles can last for months and even years.

In 1998 two new drugs for the treatment of shingles were introduced. They are valacyclovir (trade name Valtrex) and famciclovir (trade name Famvir). Both prevent the virus from reproducing if taken within seventy-two hours after the rash first appears. Certain restrictions apply to the use of both drugs.

PREVENTION

A vaccine for chickenpox called Varivax was approved for use in the United States in 1995. The vaccine consists of live, but weakened, viruses and is effective in preventing chickenpox in 70 to 90 percent of all cases. In the remaining 10 to 30 percent of cases, the severity of a chickenpox infection is lessened by the vaccine. The U.S. Centers for Disease Control and Prevention recommend that all children (with a few exceptions) be given the vaccine between the ages of twelve and eighteen months. It can be combined with their measles-mumps-rubella vaccination. The vaccine is also recommended for older people who may be at risk for the disease. Health care workers and women of childbearing age are examples of such groups.

Children under the age of twelve receive one dose of the vaccine. Those over the age of twelve receive a second dose four to eight weeks after the first dose. The vaccine is useful when given soon after someone has been exposed to chickenpox. It can also prevent the disease if given during the incubation period.

The Varivax vaccine is still not widely used. Some doctors believe that a second dose later in life may be necessary to protect individuals and worry that individuals may not remember to get the second dose once they grow up. Other doctors are concerned that the live virus in the vaccine might cause shingles later in life. Because of such fears, only 20 percent of all two-yearolds had been vaccinated for chickenpox as of 1997. Health professionals are still debating the best way to use Varivax.

A substance known as varicella-zoster immune globulin (VZIG) is also available for the treatment of children with weakened immune systems and others at risk for complications from chickenpox. To be effective, the drug must be given within ninety-six hours after a person has been exposed to the virus. In such cases, it can reduce the severity of chickenpox symptoms.

FOR MORE INFORMATION

Books

The Burton Goldberg Group. Alternative Medicine: The Definitive Guide. Puyallup, WA: Future Medicine Publishing, 1993.

Silverstein, Alvin, Virginia Silverstein, and Laura Silverstein Nunn. Chicken Pox and Shingles. Hillside, NJ: Enslow Publishers, Inc., 1998.

Weitzman, Elizabeth. Let's Talk about Having Chicken Pox. Powerkids Press, 1997.

Periodicals

Kump, Theresa. "Childhood without Chickenpox? Why Parents Are Still Wary of This New Vaccine." Parents Magazine (April 1996): pp. 39–40.

Napoli, Maryann. "The Chickenpox Vaccine." Mothering (Summer 1996): pp. 56–61.

Organizations

Centers for Disease Control and Prevention. National Immunization Hotline. 1600 Clifton Road, NE, Atlanta, GA 30333. (800) 232–2522 (English).(800) 232–0233 (Spanish). http://www.cdc.gov.