1. Take the Chickenpox Quiz!
2. Childhood Skin Problems Slideshow
3. View Images of Chickenpox (Varicella)

Medical Author:

John Mersch, MD, FAAP

John Mersch, MD, FAAP

Dr. Mersch received his Bachelor of Arts degree from the University of California, San Diego, and prior to entering the University Of Southern California School Of Medicine, was a graduate student (attaining PhD candidate status) in Experimental Pathology at USC. He attended internship and residency at Children's Hospital Los Angeles.

View Full Profile

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

Rash

Healthy children generally experience one to two days of fever, sore throat, and malaise approximately two weeks following exposure to VZV. Within 24 hours of these symptoms, a characteristic rash develops initially on the torso and then spreads over the next seven to 10 days outward to the head, arms, and legs. The rash progresses through a predictable evolution from a red papule ("bug bite" appearance) to blister (vesicle) to pustule and then scabs over. The vesicle and pustular fluids are highly concentrated with infectious virus particles. New lesions characteristically come in "waves" over the skin surface. The patient may thus have newly formed papules, middle-aged vesicles and pustules, and crusted lesions all at the same time. At the peak of the disease, a patient may have over 300 skin lesions at one time. Once all lesions are scabbed over and no new lesions are developing, the person is no longer contagious. The lesions rarely cause permanent scarring, unless secondary infection develops (see below). Lesions may commonly be found in the mouth and may also involve the genitalia.

Complications

In healthy children, chickenpox is a mild disease. Adults are 25% more likely to have significant complications from the diseases. Common complications affecting both children and adults include the following:

• Skin infection: Secondary bacterial infections caused by either Staphylococcus or Streptococcus bacteria are well described. Rarely, an invasive form of Streptococcus can quickly spread throughout the body and may be life-threatening.
• Pneumonia: This is a relatively rare complication in healthy children but is the primary cause of hospitalization for adults (occurring in one in 400 cases) and has a mortality (death) rate of between 10%-30%.
• Neurologic complications: Children most commonly develop an inflammation of the balance center of the brain called acute cerebellar ataxia. Symptoms of abnormal eye movements and poor balance develop in about one in 4,000 children approximately one week into the skin manifestations of chickenpox. Symptoms generally last for a few days, and a complete recovery is common. Adults more commonly develop a more generalized brain inflammation ("encephalitis") whose symptoms may include delirium and seizures. Some studies report a 10% mortality rate and a 15% rate of developing long-term neurologic side effects in survivors.
• Reye syndrome: This rare childhood complication of chickenpox (and influenza) is most commonly associated with the administration of aspirin. A rapid progression of nausea, vomiting, headache, delirium, and combativeness that may progress to coma is a common pattern of deterioration. Supportive measures are the only therapy.
• Rare complications: Hepatitis, kidney disease, ulcers of the intestinal tract, and inflammation of the testes (orchitis) have all been described.

Chickenpox and pregnancy

The first case of pregnancy-associated complications of VZV was reported in 1947. Further studies have shown that most cases of congenital (in the womb) infection occur in infants whose mothers were infected with VZV between eight and 20 weeks gestation. Congenital infection occurs only in infants born to mothers who experience VZV clinical infection (chickenpox) during pregnancy. Women who are immune to VZV and are exposed to chickenpox during pregnancy do not carry the same risk profile for their infant. Studies indicate that the risk of fetal anomalies as a result of congenital VZV infection is very small (0.4%-2%). Complications that have been documented include skin pigment abnormalities and scarring (presumably due to intrauterine skin infections), eye abnormalities, brain structural abnormalities resulting in mental retardation, and structural abnormalities of the arms and legs. Maternal shingles during any trimester of pregnancy has not been associated with congenital abnormalities. Non-VZV-immune pregnant women can be reassured that localized shingles (zoster) infection is only contagious from direct contact with open lesions.

Maternal VZV infection during the final two weeks of a pregnancy carries an ominous risk for the infant. Infected infants have up to a 25% mortality rate, and the worse prognosis exists for those infants whose mothers develop chickenpox during the last five days of confinement. Overwhelming generalized sepsis (infection of the bloodstream that spreads throughout the body) and multiple organ infection and failure lead to such a dismal prognosis. Specific anti-VZV gamma globulin can be used to lessen the severity of neonatal disease (see below).

Must Read Articles Related to Chickenpox

Fever in Children Fever is defined as a rectal temperature over 100.4 F or 38.0 C. Fever isn't life-threatening unless it is persistently high -- greater than 107 F rectal temper...learn more >>

Immunization Schedule, Adults At least 45,000 adults in the United States die of complications of influenza, pneumococcal infections, and hepatitis B each year. These diseases, and others th...learn more >>

Immunization Schedule, Children Vaccinations are some of the most important tools available for preventing disease. Most children get all their shots during childhood. Parents should consult t...learn more >>

See the Entire Chickenpox Topic Guide »