Chickenpox

Also called Varicella

Usually a mild childhood illness. Not mild in newborns, pregnancy, or anybody immunosuppressed.

What it is

Chickenpox is caused by the varicella-zoster virus. Most people in the UK have it in childhood, when it is usually mild.

It is highly infectious, spreading through the air and by contact with the blisters, from two days before the rash appears until every spot has crusted over.

The reason for an entry here is who it is dangerous for. Newborns, pregnant people who are not immune, and anybody immunosuppressed by treatment or illness can become seriously unwell, and exposure in those groups needs urgent advice rather than watchful waiting.

After the illness, the virus stays dormant and can reactivate decades later as shingles. Somebody with shingles can give an unprotected person chickenpox, though not shingles.

Signs you might notice

Itchy spots appearing in crops, starting on the chest, back and face, becoming fluid-filled blisters then crusting.

Fever, headache and feeling unwell, often before the rash.

Spots at different stages at the same time, which is characteristic.

Warning signs: spots becoming hot, red and painful with spreading redness, which suggests bacterial infection; breathlessness; drowsiness; severe headache; or dehydration.

In an adult it is usually more severe than in a child.

How it can affect day-to-day life

Ibuprofen should be avoided in chickenpox. There is an association with serious skin infection, and paracetamol is the safer choice.

Scratching causes scarring and bacterial infection, and keeping nails short and using cool cotton clothing helps more than any lotion.

Exclusion is until all spots have crusted, usually around five days after the rash starts.

Anybody who has been in contact and is pregnant, newborn or immunosuppressed should seek advice the same day, because preventive treatment exists and is time-limited.

Supporting someone well

Use paracetamol, not ibuprofen.

Keep the person cool, use loose cotton clothing, keep nails short, and consider mittens for babies.

Cooling gel or an antihistamine at night helps the itch.

Keep fluids up; a sore mouth from spots reduces drinking.

Keep away from pregnant people, newborns, and anybody immunosuppressed until crusted.

Seek urgent advice for exposure in those groups.

Watch for skin infection: a spot becoming hot, painful and surrounded by spreading redness.

Where to get help

Call 111 for advice. Most cases need no medical treatment.

Same-day advice for exposure in pregnancy, in a newborn, or in anybody immunosuppressed.

999 or A and E for breathlessness, drowsiness, seizures, or a rapidly spreading painful red rash.