Chickenpox is often thought of as a harmless childhood viral infection. Indeed it is often harmless in most children and common throughout the world. After infection, a person has lifelong immunity against the disease although the virus can become reactivated to cause shingles, but not chickenpox. However, some people do not get the chickenpox in childhood and women are at risk if they develop chickenpox during pregnancy. It is not the mother that is at risk but rather the unborn child who may be at risk of being born with birth defects. This is known as congenital varicella syndrome.
Understanding more about chickenpox is important for pregnant women who have never had the infection earlier in life. Chickenpox is one of the most common childhood diseases although vaccination has reduced the incidence but susceptible adults may still contract the infection if they did not do so earlier in life. Chicken pox is caused by the varicella zoster virus which can spread from person to person easily. Usually chicken pox resolves without treatment in most cases but anitivirals are sometimes recommended to prevent complications. Adults tend to suffer a worse infection than children but it is still unlikely to lead to complications.
Symptoms of chicke pox usually appears in phases. Early symptoms (prodromal) involves symptoms which arise before the appearance rash of chicken pox in adults. The symptoms are :
- Poor appetite
- Head and body ache
- Abdominal pain
- Feeling of discomfort
- Appearance of rash
In children there is no prodromal phase and appearance of typical rash is the first symptom. The rashes appear as small dots mainly on the head, scalp, trunk and fewer in the limbs. Painful lesions may affect the inner lining of the mouth and upper part of the throat or external genitalia. The small pinhead rashes graduall becomes fluid-filled itchy blisters which in due course of time form scab (hard, dried brownish cover) and finally heal usually without scaring.
Complications of Chickenpox
The symptoms usually appear within 10 to 21 days of contact with infected person. The period of infectivity lies in between 1 to 2 days prior to appearance of rash to until scab formation (4 to 5 days after appearance of rash). Chickenpox is usually a self limiting disease (resolves on its own) without any complications in children. Complications may occur in
- Unborn babies of mothers who have the infection during pregnancy.
- Immunocompromised persons like those with HIV/AIDS, long term steroid or cancer drug intake.
- Eczema patients.
The complications are :
- Congenital varicella syndrome in newborns.
- Secondary bacterial infection of skin and lungs (pneumonia).
- Reye’s syndrome in children.
- Rarely brain (encephalitis) or heart (myocarditis) involvement.
Another very common late complication of chickenpox is shingles, affecting one out of three adults who had chickenpox earlier in life. The chickenpox virus after remission of attack remains dormant in the nerve tissue for years. If the immunity of the person is compromised in any way or there is stress, the virus may become active again and cause painful blisters (shingles). The pain is very severe and persists even after healing of the blisters (postherpetic neuralgia).
What Causes It?
Infection with varicella zoster virus leads to chickenpox. Being highly contagious, the virus spreads from infected person via coughing, sneezing or in contact with fluids from blisters. The infection is usually mild in young children (1 to 10 years) but in older children and adults it is comparatively more debilitating. Chickenpox very rarely occurs in the same person twice. A person who has never has the infection before, never had the vaccination and are in close contact with an infected person is more likely to contract the infection.
Usually chicken pox does not require any specific treatment apart from supportive measures like bed rest, ample fluid intake and antihistaminics to relieve itching. Calamine lotion also eases the itching and helps keep the blisters from becoming infected. Patients need to be aware that apart from a secondary bacterial infection, they are also at risk of severe scarring but scratching. Antivirals (acyclovir) are prescribed in people who are at high risk of developing complication.