Chickenpox

A highly contagious viral infection that causes an itchy, blistering rash and fever. It's usually mild in children.

InfectionSkinLast updated: 21 October 2026

Quick Summary

Primary Symptoms

An itchy rash of red spots that turn into fluid-filled blisters and then crust over, with fever and tiredness.

Common Treatments

Rest, fluids, paracetamol and calamine for itching. Antivirals for adults, pregnant women and people at higher risk.

Risk Factors

Not having had chickenpox or the vaccine, close contact with someone who has chickenpox or shingles.

OverviewSymptomsCausesTreatmentFAQ

Overview

Chickenpox is caused by the varicella-zoster virus. It spreads easily through the air and by touching the blisters.

It's usually mild in children but can be more serious in adults, pregnant women, newborns and people with weak immune systems. After chickenpox, the virus stays in the body and can return later as shingles.

Symptoms

Itchy blistering rash

Spots appear in crops, turn into blisters and then scab over.

Fever

Often before or with the rash.

Tiredness and aches

Feeling generally unwell.

Warning signs

Breathing difficulty, a very red or painful rash, or confusion need urgent care.

Causes & Risk Factors

Biological Causes

Infection with the varicella-zoster virus. People are contagious from about two days before the rash until all the blisters have crusted.

Key Risk Factors

  • No immunity Not having had chickenpox or the vaccine.
  • Close contact Living with or being near someone with chickenpox or shingles.
  • Higher risk groups Adults, pregnant women, newborns and people with weak immunity have more complications.

Management & Treatment

01. Symptom relief

Paracetamol for fever (avoid ibuprofen and aspirin), calamine lotion and cool baths for itching.

02. Antiviral medicine

Aciclovir may be prescribed for adults or people at higher risk.

03. Stay home

Keep away from school or work until all spots have crusted over.

Frequently Asked Questions

Can you get chickenpox twice?
It's rare. Most people are immune for life after one infection.
Is there a vaccine?
Yes, the varicella vaccine is available and recommended for children and non-immune adults.
What should pregnant women do?
Contact a doctor promptly if exposed and not immune.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.