Chicken pox (medical term for which is Varicella) is a self-limiting viral illness, usually acquired through the inhalation of very small droplets from an infected person. It is largely a childhood disease, with >90 % cases occurring in children younger than 10 years. While unpleasant to the sight while rash lasts, it is largely a harmless disease. In adults, however, it can have serious complications. Since the introduction of immunization in children, the incidence of chicken pox has greatly decreased worldwide.
SIGNS AND SYMPTOMS
Presenting symptoms of chicken pox may include a history of recent low grade fever, abdominal pain, a history of rash and intense itching, nausea, decreased appetite, headache, cough and flu-like symptoms.
Rash and fever are the typical findings in children presenting with chicken pox. Low grade fever generally precedes the rash by 1-2 days. Children with eczema or other underlying skin diseases may have severe skin presentations with chicken pox. Generally, a patient presenting with chicken pox will not look too ill, however, a very sick appearance of the child should raise concern for complications of the disease, especially in already immunocompromised kids.
Chicken pox has a very characteristic rash, called vesicular rash, which appears in crops. The lesions are fluid filled, and appear in clusters, in different stages of progression. Such a rash which is in different stages is the hallmark of chicken pox. An otherwise healthy child will generally have 200-250 lesions, with some having as few as 10, or as many as 1000. Common areas for the rash to appear are the face, hands, arms and the chest and abdomen. The rash usually does not progress to the lower body, and is self resolving once crusting of the lesions happens. The rash will generally not leave any scars unless scratched.
Fever is usually low grade, 100 F-102 F, but in some cases may present with as high a fever as 106F. Fever in chicken pox does not last for more than 4 days. Fever longer than this duration should prompt concern for underlying disease/complications.
CHICKEN POX IN PREGNANCY
Pregnant women who have not had chicken pox, or who are known to not have immunity against chicken pox, should avoid contact with persons who have chicken pox or shingles, and should promptly inform their doctor of potential exposure. After exposure in pregnancy, chances are still good that your baby would be fine. But if you get chicken pox during the first or second trimester, there’s a slight risk (less than 2 percent) that your baby could get congenital varicella syndrome. In the UK, it’s estimated that just 3 in every 1,000 women (0.3%) catch chickenpox during pregnancy. Risk is highest if you’re infected between weeks 13 and 20 of pregnancy.
There is no cure for chicken pox as it is a self-limiting viral disease which will clear up by itself in 7-10 days after onset of fever. However, it is advisable to take measures to limit the discomfort from itching which can be intense, and fever. Painkillers such as paracetamol can be used to control fever. NSAIDS such as ibuprofen (Nurofen) are best avoided in chicken pox as there is a very small risk of getting an adverse skin reaction.
It is also important for children and adults with chicken pox to drink plenty of water during the illness to prevent dehydration. Avoid any foods that maybe difficult to swallow, as sometimes the rash can affect the throat/upper esophagus, causing swallowing to be very painful.
Chicken pox rash can be extremely itchy, but it is important not to scratch at the lesions to avoid future scarring. Fingernails should be kept very short, and children should wear mitts at night to prevent scratching while asleep. Calamine lotion can be used to soothe the itching/burning sensation. if very severe itching, a prescription of chlorphenamine should be obtained from your GP. Similarly, loose fitting, cool clothing should be worn so as to not aggravate the skin further.
For severe cases of chicken pox, antiviral medicines are available which can improve the outcome of the disease and control the symptoms. For the most part, these agents are safe to use in pregnant women as well as new born babies which might have been exposed to the virus in utero. The most common antiviral agent used is Acylovir. Ideally, acyclovir should be started within 24 hours of the rash appearing. Treatment with acyclovir lasts 5-7 days and is taken in divided doses. Dose is calculated according to body weight.
Immunoglobulin is a solution of antibodies that is taken from healthy donors. Varicella-zoster immunoglobulin (VZIG) contains antibodies to the chickenpox virus.
Immunoglobulin treatment for chicken pox is given by drip. It is not used to treat chickenpox but to protect people who are at high risk of developing a severe chickenpox infection. This includes:
- pregnant women
- newborn babies
- people with weakened immune systems
In the case of pregnant women, immunoglobulin treatment also reduces the risk of the unborn baby becoming infected.
Never give your child aspirin if you suspect or know that they have chickenpox.
Children with chickenpox who take aspirin can develop a potentially fatal condition called Reye’s syndrome, which causes severe brain and liver damage.