Chickenpox

Overview

Chickenpox (varicella) is caused by the varicella-zoster virus, a member of the herpes virus family that infects only humans. It spreads very easily from person to person, by touching the fluid in the blisters or by breathing in droplets from an infected person's breath. In a home, most people who have never had it will catch it from a family member who has it.

The rash usually starts about two weeks after contact with the virus. Before the rash, there may be fever, tiredness, headache and poor appetite for a day or two. The spots first appear on the scalp, face or chest and then spread. Each spot becomes a small blister full of fluid and then dries into a scab. New spots keep coming for several days, so spots, blisters and scabs are seen at the same time. A person can pass it on from 1 to 2 days before the rash appears until every spot has scabbed over.

Most children have a mild illness. Adults, pregnant women, newborn babies and people with a weak immune system are more likely to become seriously ill. After the illness, the virus stays asleep in the nerves for life and can wake up years later as shingles (herpes zoster). In warm countries, more people reach adult life without having had chickenpox, so more adults catch it. A vaccine is available.

Symptoms

• An itchy rash of red spots that can appear anywhere, including inside the mouth and around the genitals
• Spots that fill with fluid to become blisters and then crust into scabs
• New crops of spots for several days, so spots, blisters and scabs are seen together
• Fever (high temperature), often starting a day or two before the rash
• Tiredness, aches and feeling generally unwell
• Headache and sometimes mild tummy pain
• Loss of appetite

Causes and risk factors

Causes

• Infection with the varicella-zoster virus, which causes both chickenpox and shingles
• Touching the fluid from the blisters of someone with chickenpox
• Breathing in droplets from the breath of an infected person
• Less often, contact with someone who has shingles, if you have never had chickenpox

What makes it more likely

• Never having had chickenpox or the chickenpox vaccine
• Living in the same home as someone with chickenpox
• Living in a warm (tropical) country, where more people reach adult life without having had it
• Living or working in crowded places, such as hostels, barracks or training centres
• Being an adult, as the illness is usually more severe than in children
• Being pregnant and not immune
• Being a newborn baby, especially if the mother catches chickenpox around the time of birth
• Having a weak immune system, for example from advanced HIV or medicines that lower immunity

Complications

Most cases settle without problems. Scratched spots can become infected with bacteria, which can cause a spreading skin and soft-tissue infection. The virus can also affect the lungs (pneumonia), the liver and the brain. Problems with balance and walking (cerebellar ataxia) are uncommon and usually get better, while swelling of the brain (encephalitis) is rare but more serious. Adults, and especially pregnant women near the time of birth, are more likely to get chickenpox pneumonia. If a woman catches chickenpox in the first half of pregnancy, a small number of babies are born with scarring and problems of the limbs, brain or eyes. Newborn babies can become very ill. Scratching can leave scars, and the virus can return later as shingles.

Are you a PMDC-registered doctor who treats Chickenpox? List your profile free.

Diagnosis

Chickenpox is usually diagnosed by a doctor or pharmacist simply by looking at the rash. The mix of spots, blisters and scabs, mostly on the body, face and scalp, is typical. No test is needed in most healthy children.

A test is used when the diagnosis is not clear or the person is at high risk, such as in pregnancy, a newborn or someone with weak immunity. The preferred test is PCR (a test that finds the virus's genetic material) on a swab taken from a blister. In severe illness, PCR can also be done on other samples, such as fluid from around the brain. A blood antibody test mainly shows whether a person has had chickenpox in the past and is immune, which can help after a pregnant woman has been exposed.

Treatment

1. For most healthy children, chickenpox gets better on its own. Treatment aims to ease fever and itching and to stop scratching.
2. Use paracetamol for fever or pain if needed. Your doctor or pharmacist decides the dose. Do not use ibuprofen unless a doctor advises it, and never give aspirin to children or teenagers.
3. For itching, use cooling creams, gels or emollients (moisturisers) from a pharmacy, and ask the pharmacist about an antihistamine.
4. See a doctor within 24 hours of the rash starting if you are a teenager or adult, smoke, have a severe rash or severe pain, or caught it from someone in your home. The doctor may consider an antiviral medicine, which works best when started early.
5. Pregnant women, newborn babies and people with a weak immune system need specialist advice quickly. Some will need antiviral medicine through a drip in hospital.
6. People at high risk who have been near someone with chickenpox may be offered antiviral medicine or a varicella-zoster immunoglobulin (antibody) injection to lower the chance of severe illness.
7. If spots become infected or complications such as pneumonia develop, a doctor will treat these, sometimes in hospital.

Medicines in Pakistan

Medicines a doctor may use, by group. Read the role: some are only for special cases. Each link opens our page for that medicine, with every brand and its official DRAP price. Your doctor decides which medicine and dose are right for you.

Also used (not yet in our price list): Valaciclovir, Famciclovir, Varicella-zoster immunoglobulin (VZIG)

Self-care and prevention

Self-care

• Drink plenty of fluids; ice lollies can help a child who will not drink
• Keep fingernails short and clean, and put socks or mittens on a child's hands at night to reduce scratching
• Try not to scratch the spots, as this can cause infection and scarring
• Bathe in cool or lukewarm water and pat the skin dry gently
• Use cooling creams, gels or emollients from a pharmacy to soothe the itch
• Wear loose, comfortable clothes
• Stay off school, college or work until all the spots have scabbed over, usually about 5 days after they first appeared

Prevention

• Ask your doctor about the chickenpox vaccine, which protects well against severe illness
• Keep a person with chickenpox away from pregnant women, newborn babies and people with weak immunity until all spots have scabbed
• If you are pregnant and not immune, avoid people with chickenpox or shingles, and see a doctor quickly if you are exposed
• Stay at home while infectious, from the start of the rash until every spot has crusted over
• Wash hands well and avoid touching the blisters of someone who has chickenpox or shingles

Common questions

How long is chickenpox contagious?

A person can spread chickenpox from 1 to 2 days before the rash appears until all the spots have formed scabs. This is usually about 5 days after the spots first appeared. They should stay at home during this time.

Can I give ibuprofen for chickenpox?

Do not use ibuprofen for chickenpox unless a doctor advises it, because it is linked with serious skin infections. Paracetamol can be used for fever and pain. Never give aspirin to children or teenagers.

Can you get chickenpox twice?

Most people get chickenpox only once. However, the virus stays in the body for life and can come back years later as shingles, a painful rash usually on one side of the body. Someone with shingles can pass on chickenpox to a person who has never had it.

Is chickenpox dangerous in pregnancy?

It can be. Pregnant women are more likely to get chickenpox pneumonia, and infection in the first half of pregnancy can rarely harm the baby. If you are pregnant, have not had chickenpox or are not sure, and have been near someone with it, contact your doctor straight away, as treatment to prevent severe illness may be offered.

Is there a vaccine for chickenpox?

Yes. Chickenpox vaccines are safe and well tolerated in healthy people and protect very well, especially against severe illness. They are live vaccines, so they are not given to people with severe immune weakness. Ask your doctor or a vaccination centre whether it is suitable and where to get it.

Sources

1. World Health Organization (Weekly Epidemiological Record; full text read from the PDF copy on the NITAG Resource Center). WHO position paper on varicella vaccines – November 2025 (2025).
2. HSE Antimicrobial Resistance and Infection Control Programme (Ireland). Chickenpox (Varicella Zoster) Antiviral Prescribing, V2.1 (2022).
3. NHS 111 Wales. NHS 111 Wales - Health A-Z : Chickenpox (n.d.).
4. Weekly Epidemiological Monitor (record on search.bvsalud.org). Upsurge of Chickenpox in Pakistan (2018).
5. Pakistan Armed Forces Medical Journal. OUTBREAK OF CHICKENPOX IN A MILITARY CENTER IN NORTHERN PAKISTAN: Outbreak of Chickenpox (2016).

Prepared from the sources listed below by the MedInfoBase team. Last reviewed 16 October 2026. This page is general health information, not medical advice. It gives no doses and does not replace a doctor: talk to your doctor or pharmacist before starting, stopping or changing any medicine. How we write and check our pages.

Related conditions

MeaslesImpetigoPneumonia

All health conditions