Quick answer: Chickenpox is a rite of passage for most children — highly contagious, recognisable, and in healthy children, generally self-limiting.
Chickenpox is a rite of passage for most children — highly contagious, recognisable, and in healthy children, generally self-limiting. Here’s what to expect and when to be more concerned.
What to Expect: The Course of Chickenpox
Chickenpox (varicella) is caused by the varicella-zoster virus. The incubation period is 10–21 days. The typical course: Day 1–2: Fever, feeling unwell, mild headache — prodromal phase. Day 2–4: Rash appears — starts as small red spots that quickly develop into fluid-filled blisters (vesicles), then cloud over and crust. New spots appear in crops over 3–5 days — you’ll see spots at all stages simultaneously. Rash appears first on the trunk, then spreads to face, scalp, and limbs. Day 5–7: All spots crusted over. Contagious from 2 days before the rash until all spots have crusted — approximately 5–7 days after the rash starts. The itch is often intense and is the most distressing symptom.
Treatment at Home
Paracetamol for fever and discomfort. Do not use ibuprofen — ibuprofen use in chickenpox is associated with serious secondary bacterial infections (invasive group A Streptococcus). Antihistamine (chlorphenamine / Piriton in the UK, diphenhydramine in the US) helps with itch, especially at night. Calamine lotion has modest evidence for itch relief. Cool baths with a handful of oats (oatmeal baths) are soothing. Keep nails short and clean — scratching introduces bacteria and causes scarring. Dress in cool, loose clothing.
When to Seek Medical Attention
Contact your GP or seek urgent care for: chickenpox in a baby under 4 weeks (very high risk group), severe bacterial skin infection (spreading redness, warmth, pus — can indicate cellulitis or streptococcal infection — this is the most common serious complication), high fever that doesn’t respond to paracetamol, difficulty breathing or chest pain, drowsiness or difficulty walking, severe headache or stiff neck, vomiting that persists after the fever has resolved, and any child who is immunocompromised, on oral steroids, or has a condition affecting the immune system.
The Vaccine
The chickenpox (varicella) vaccine is part of the routine immunisation schedule in the US (given at 12–15 months and 4–6 years). In the UK, NHS England introduced routine varicella vaccination from 2026 as part of the MMRV (measles, mumps, rubella, varicella) programme — given at 12 months and 18 months, replacing the previous MMR schedule. Children born from April 2024 onwards are eligible for the routine programme. Prior to 2026, the vaccine was available privately in the UK; unvaccinated older children may still benefit from private vaccination — discuss with your GP. The vaccine is approximately 80–85% effective at preventing chickenpox and over 95% effective at preventing severe disease. Vaccinated children who do get chickenpox typically have a much milder illness.
Contagion and School Exclusion
Chickenpox is highly contagious — from 2 days before the rash until all spots have crusted. UK guidance: children should stay home until all blisters have crusted (typically 5 days after rash onset). Inform the nursery/school so they can notify parents of at-risk children (pregnant women who haven’t had chickenpox, immunocompromised people). Adults who haven’t had chickenpox and haven’t been vaccinated who are exposed may consider post-exposure prophylaxis (varicella-zoster immune globulin within 96 hours).
Frequently Asked Questions
Can my baby get chickenpox twice?
Natural chickenpox infection typically provides lifelong immunity in healthy people. Reinfection is rare but possible, particularly in immunocompromised individuals. The varicella-zoster virus remains dormant in nerve ganglia after primary infection and can reactivate later in life as shingles (herpes zoster) — particularly in older or immunocompromised adults.
My baby has chickenpox — can they give it to a pregnant person?
Yes — and this is important. Chickenpox in pregnancy can cause varicella pneumonia (serious), foetal varicella syndrome (rare, causing birth defects), and neonatal varicella (if exposure is near delivery). Pregnant women who haven’t had chickenpox should avoid contact with active cases and should contact their obstetrician immediately if exposure occurs.
Are the scars from chickenpox permanent?
Most chickenpox spots heal without scarring. Scars occur when spots are scratched and secondary bacterial infection develops, causing deeper tissue damage. Keeping nails short, treating itch with antihistamines, and preventing scratching are the best scar prevention strategies.
Related Reading
- Rashes in babies: a visual guide to common skin conditions
- Baby fever: temperature chart and when to seek help
- Can I give my baby paracetamol?
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