Chickenpox in Children: What It Looks Like and How It Spreads

The chickenpox rash: stages and timing

Chickenpox typically begins with one to two days of mild fever, fatigue, and loss of appetite, followed by the rash 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication. The rash starts as small red flat spots, usually first on the scalp, face, or trunk, that rapidly progress to fluid-filled blisters (vesicles) that are intensely itchy. These blisters then break open and crust over. Illness typically lasts 4–7 days.

A distinctive feature of chickenpox is that all three stages — spots, blisters, and crusts — are visible simultaneously on the body 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication. New waves of spots can appear over several days, meaning a child may have some areas crusting while new blisters are still forming elsewhere. The rash can spread to the mouth, eyelids, and genitals.

How contagious is chickenpox, and for how long?

Chickenpox is one of the most contagious childhood illnesses — approximately 90% of unimmunized people become infected after exposure 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication. It spreads through respiratory droplets (coughs, sneezes) and through direct contact with the fluid from blisters. The contagious window begins one to two days before the rash appears and lasts until all blisters have crusted over — typically about five to seven days from when the rash started 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication.

Children should not return to school, childcare, or group settings until every blister has formed a dry crust.

Who faces higher risk from chickenpox

Chickenpox is often described as a routine childhood illness, but it can cause serious complications in specific groups 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication:

• Newborns whose mothers develop chickenpox just before or after delivery face significant risk of serious disease
• Immunocompromised children receiving steroids, chemotherapy, or other medications that suppress the immune system are vulnerable to severe disease
• Unvaccinated adolescents and adults tend to have more serious illness than young children

If a child with any of these risk factors is exposed to chickenpox, contacting a healthcare provider promptly — not waiting to see if the rash develops — is recommended, as antiviral medication or immune globulin may be appropriate preventively 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication.

Managing the itch and fever at home

Keeping a child comfortable means addressing the itch, which can be severe. Trimming fingernails short and keeping hands clean reduces the chance of scratching the blisters open and introducing a bacterial skin infection — the most common complication of chickenpox in children 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication. Cool baths with colloidal oatmeal, loose cool clothing, and age-appropriate antihistamines may help with itch.

Aspirin must not be given to children with chickenpox (or any viral illness in children). The use of aspirin in children with chickenpox is associated with Reye syndrome, a severe condition affecting the liver and brain that can be fatal 2Ref 2Centers for Disease Control and Prevention (2024).How to Treat Chickenpox.Aspirin contraindicated in children with chickenpox due to Reye syndrome risk; ibuprofen associated with life-threatening bacterial skin infections; acetaminophen preferred for fever.

Ibuprofen should be avoided if possible during chickenpox. The CDC notes that the American Academy of Pediatrics recommends avoiding ibuprofen because it has been associated with life-threatening bacterial skin infections during chickenpox 2Ref 2Centers for Disease Control and Prevention (2024).How to Treat Chickenpox.Aspirin contraindicated in children with chickenpox due to Reye syndrome risk; ibuprofen associated with life-threatening bacterial skin infections; acetaminophen preferred for fever. Acetaminophen is the preferred fever-reducing medication during chickenpox.

Shingles and the connection to chickenpox

After a chickenpox infection, the varicella-zoster virus stays dormant in nerve tissue. Years or decades later, it can reactivate as shingles — a painful, blistering rash along a nerve path 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Rash stages, contagiousness (90% attack rate), duration 4-7 days, 97% case reduction with vaccine, high-risk groups, bacterial skin infection as most common complication. The chickenpox vaccine significantly reduces the risk of shingles later in life compared to natural infection. Children who had chickenpox can still develop shingles, though it is less common in children than in older adults.