What is chickenpox?


It is a viral disease caused by first exposure to the varicella zoster virus. The disease presents with fever and blistered rash. The virus then remains latent or dormant in the body.

How does chickenpox spread?


The virus commonly spreads from person-to-person by air-borne droplets. This spread occurs when an infected person coughs or sneezes and causes dispersion of droplets of respiratory secretions in the surrounding air. It can also spread by direct contact with the chickenpox or herpes lesions as these contain infectious fluid.

When is chickenpox contagious?


Chickenpox is contagious from two days prior to appearance of the rash till all the lesions are covered by a scab, which occurs usually by 4-5 days of the rash. However, the transmission is most likely within first two days before the appearance of the rash.

Can chickenpox be prevented?


Chickenpox is a highly contagious disease. Following a case of chickenpox, up to 90% of susceptible children and adults who come in close contact with the case can develop infection. Therefore, when one child develops chickenpox, many susceptible children in the school and persons in the child's house develop the disease.

Isolating the infected child and avoiding contact with him can prevent spread of infection. However, chickenpox is most infectious before the rash develops when there is no reason to suspect that he has chickenpox. Such a child, during this period, may continue to attend school, play with his playmates and therefore spread the disease.

Once a child has come in contact with a case of chickenpox, he can be immunized with antibodies (varicella zoster immunoglobulin) against the virus. However, for the immunization to be effective, it has to be given within 3-4 days of exposure. It is costly and offers protection only for a few weeks. Vaccination against chickenpox is now available and offers long-term protection against the disease.

Is chickenpox only a childhood disease?


Many people contract chickenpox during childhood or adolescence, but adults who have not been infected before are susceptible to infection and can develop chickenpox in adulthood if and when they come in contact with a case.

What are the symptoms of chickenpox?


Chickenpox presents with a characteristic rash. The rash first appears over the face, scalp or trunk. The rash initially consists of red / purple colored raised lesions (maculo-papular rash) which evolve into lesions filled with clear fluid. These lesions are called vesicular lesions. The fluid in these lesions then becomes hazy given the rash a characteristic blistered or pustular appearance. Most children have 200-300 lesions, which appear in successive crops and hence at a given time different types of lesions are present. The lesions then form a crust after 4-5 days of appearance. The crusts fall off after a week or two.

The rash is itchy and a young infant may get irritated due to the constant itch. Other common symptoms include fever, nausea and anorexia, bodyache, vomiting, listlessness, etc.

Is chickenpox a totally harmless disease in children?


In a vast majority of children chickenpox is not associated with any complications. Secondary bacterial infection affecting the skin lesions is the commonest complication that one encounters. In a minority of children, the virus could prove more aggressive and cause infection in the lungs leading to pneumonia and may affect the brain leading to swelling and infection of the brain (encephalitis). Such a child may develop unconsciousness and convulsions. These could prove fatal. Occasionally, virus may affect small brain (cerebellum) resulting in difficulty in walking. Many other complications are described. But these usually have a self-limited course. Most children get away with only a few scars that remain to the skin once the crusts fall of. At times, the scarring may be unsightly, which may cause cosmetic concerns later in life.

What happens if an adolescent or adult contracts chickenpox?


Chickenpox is more severe in adolescents and adults than in children. The fever is higher and continuous for much longer. The rash is much heavier. The likelihood of complications is greater, too. They are more likely to suffer from pneumonia. The risk of complications and death tend to be higher when chickenpox is contracted later in life.

Who are more likely to suffer from chickenpox?


Anyone who has not suffered from chickenpox previously is at risk of developing it. If a mother has antibodies against chickenpox in her blood, she passes them on to her baby. These remain in the baby's blood for 9-12 months protecting him from chickenpox. After this period, the infant becomes susceptible to develop the infection.

As chickenpox usually affects infants and young children, those who spend a lot of time with children, like susceptible teachers and persons running the day-care centers have more chances of contracting the infection. In addition, health care providers (doctors, nurses, and hospital personnel) are at added risk of developing the infection since they may come in contact with a case during the course of their duty.