Chickenpox: symptoms, care and prevention

Chickenpox is a contagious viral infection that causes fever and an itchy, blistering rash.

It is caused by varicella-zoster virus. Infection is often self-limiting, but severity varies, and some people need prompt clinical assessment because of their age, pregnancy, immune status or symptoms.

Chickenpox very commonly presents with fever and a rash that develops into itchy, fluid-filled blisters. New spots may appear while older ones are already crusting, so several stages can be visible together. Tiredness, reduced appetite and general discomfort may accompany the rash.

Seek urgent care for trouble breathing, marked drowsiness, confusion, a stiff neck, repeated vomiting, severe dehydration, or skin that becomes increasingly painful, hot, swollen or produces pus.

Varicella-zoster virus spreads through close contact with an infected person, airborne respiratory particles, and direct contact with blister fluid. A person can pass it on before the rash is obvious and remains infectious until all blisters have crusted.

After recovery, the virus remains inactive in nerve tissue and can reactivate later as shingles. Chickenpox and shingles are different presentations of the same virus.

Fever or feeling unwell may begin before the spots. The rash then arrives in waves, often starting on the trunk or face before spreading. Blisters gradually dry and crust. Scratching can break the skin, delay healing and allow bacteria to enter.

Avoid contact with newborn babies, pregnant people and anyone with weakened immunity while infectious. Follow local school, nursery or workplace advice about returning after illness.

Contact a clinician promptly if chickenpox is suspected during pregnancy, in a newborn, in an adult with significant symptoms, or in anyone with a weakened immune system. People taking immune-suppressing medicines also need individual advice. Do not attend a clinic without warning because the infection can spread to other patients.

A clinician can often identify chickenpox from the appearance and evolution of the rash plus exposure history. Testing may be considered when the diagnosis is uncertain or when confirmation would change management. Photographs and a remote consultation can sometimes guide initial triage.

Rest, regular fluids, loose clothing, cool bathing and short fingernails can make recovery more comfortable. A pharmacist or clinician can advise on suitable fever relief and antihistamine treatment for itching. Avoid giving aspirin to a child with chickenpox.

Antiviral treatment may be considered for people at greater risk of severe illness or in particular clinical circumstances. It works best when assessed early, so call rather than waiting if you belong to a higher-risk group.

Keep the person away from vulnerable contacts until every blister has crusted. Do not share towels or clothing, wash hands after skin care, and clean frequently touched objects. Chickenpox vaccination can reduce the chance of infection and serious illness; a clinician can advise whether it is suitable after considering age, health and previous immunity.

A GP can assess an uncertain rash, review higher-risk circumstances and decide whether antiviral therapy or testing is appropriate. A dermatologist may help when the skin appearance is atypical, healing is poor or scarring is a concern. Tell the service about suspected chickenpox before arriving.