What is chickenpox?
Chickenpox (varicella) is caused by the varicella-zoster virus. It is very contagious and spreads through the air when an infected person coughs or sneezes, and through contact with fluid from the blisters. In India, it is more common in the late winter and spring months, and outbreaks often occur in schools and hostels.
Most people get chickenpox only once. However, the virus stays in the body and can reactivate years later as shingles (herpes zoster), a painful rash usually on one side of the body. A person with shingles can pass chickenpox to someone who has never had it.
Symptoms of chickenpox
Symptoms begin about two to three weeks after exposure. Many people feel unwell with mild fever, tiredness and loss of appetite for a day or two before the rash appears. The rash then goes through stages over several days, and the number of spots can range from a few to several hundred.
- Red spots, often starting on the chest, back and face
- Spots turn into small fluid-filled blisters
- Blisters burst and form scabs
- New spots appear in crops, so all stages can be seen together
- Intense itching
How long it is contagious
A person with chickenpox can spread the virus from about one to two days before the rash appears until all the blisters have crusted over, usually about five to seven days after the rash starts. During this time, stay at home and away from school, work, pregnant women, newborns and people with weak immunity.
The diagnosis is usually made by a doctor from the look of the rash. Tests on blister fluid are only needed in unusual or severe cases. Other conditions, such as hand, foot and mouth disease, insect bites or scabies, can sometimes look similar, so check with a doctor if you are unsure.
Home care
Most children recover in about a week with simple care. Drink plenty of fluids, rest, and eat soft foods if there are sores in the mouth. Keep fingernails short and clean, and put cotton mittens on young children at night to reduce scratching, which can cause infection and scars. Wear loose cotton clothes.
A lukewarm bath can ease itching; pat the skin dry gently. Calamine lotion may soothe the skin. Paracetamol can reduce fever and discomfort; follow the label or your pharmacist's advice. There is no need to avoid bathing, and there is no evidence that any special diet is required.
Medicines to avoid and prescribed treatment
Do not give aspirin to children or teenagers with chickenpox, as it is linked to a rare but serious condition called Reye's syndrome. Avoid ibuprofen during chickenpox unless a doctor advises it, because it has been linked to serious skin infections.
Antiviral medicine such as acyclovir can reduce the severity of illness if started early. Doctors often prescribe it for adults, teenagers, pregnant women and people with weak immunity. It is given only on a doctor's prescription. Antihistamines may help with itching; ask a pharmacist which ones are suitable for children.
Who is at higher risk?
Chickenpox is usually more severe in adults than in children. Pregnant women, newborn babies, people with weak immunity (such as those with HIV, cancer, or on steroids or chemotherapy) and people with long-term skin conditions like eczema are at higher risk of complications such as pneumonia, skin infections and, rarely, brain inflammation. If you are pregnant and have been near someone with chickenpox, contact your doctor straight away, even before any rash appears.
Vaccination and when to see a doctor
The chickenpox (varicella) vaccine is safe and effective at preventing the disease or making it much milder. It is recommended for children and for adults who have never had chickenpox. It is not given during pregnancy. Ask your doctor about the right schedule for your family.
If someone who is not immune has been exposed to chickenpox, a vaccine given within a few days may prevent or soften the illness. People at high risk who cannot have the vaccine may need other protective treatment decided by a doctor. Contact your doctor soon after the exposure.
See a doctor early if you are in a high-risk group, or if any warning signs below appear. Adults with chickenpox should see a doctor within a day of the rash appearing. Your doctor or pharmacist can advise on safe relief from itching and fever.
Medicines doctors commonly use
Only your doctor can decide which medicine, dose and combination is right for you.
- Paracetamol (fever and pain reliever)Reduces fever and discomfort.Follow the label or your pharmacist's advice; avoid aspirin in children and teenagers.
- Calamine lotionSoothes itchy skin.For external use only; avoid applying near the eyes.
- Antihistamines such as cetirizine or chlorphenamineReduce itching and may help sleep.Some cause drowsiness; ask a pharmacist before giving to young children.
- Antiviral medicines such as acyclovirSlow the virus and can reduce severity when started early.Only on a doctor's prescription, mainly for adults and high-risk groups.
See a doctor urgently if
- Difficulty breathing, chest pain or a persistent cough
- Blisters that become red, hot, swollen, painful or pus-filled
- Severe headache, stiff neck, confusion, drowsiness or unsteady walking
- Chickenpox, or contact with it, during pregnancy or in a newborn
- Bleeding into the spots or a rash that looks like bruising
- Chickenpox in someone with weak immunity
Tests that may help
This article is general health information, not medical advice. Do not start, stop or combine medicines on your own — always follow your doctor's prescription and ask your pharmacist if unsure.