Chickenpox Contagious Period and Incubation Time: When Is Your Child Contagious?

Your child has chickenpox — or someone at daycare does. The first questions that come to mind are usually: How long is my child contagious? When can they go back to daycare? And what if you're pregnant?

Chickenpox (varicella) is a highly contagious viral disease that most children contract during childhood. Although the illness is usually mild in otherwise healthy children, it's important to understand the contagious period to protect others — especially newborns, pregnant women, and immunocompromised individuals.

Here's a thorough overview of the contagious period, incubation time, and daycare guidelines, based on current recommendations from the CDC and AAP.

What Is the Incubation Period?

The incubation period is the time from when your child is infected until symptoms appear. For chickenpox, the incubation period is 10–21 days, with an average of 14–16 days according to the CDC.

This means your child may have been infected 2–3 weeks ago without you knowing. During this period, the child appears healthy, but the virus is multiplying in the body.

The timeline looks like this:

• Day 0: The child is exposed to the varicella-zoster virus
• Day 10–21: Symptoms may appear (average day 14–16)
• 1–2 days before the rash: The child may have mild fever, headache, and general malaise
• The rash breaks out: Red spots that develop into fluid-filled blisters

When Is Your Child Contagious?

This is perhaps the most important question for parents. According to the CDC, your child is contagious during this period:

• From 1–2 days BEFORE the rash appears
• Until all blisters have crusted over (usually 5–7 days after the rash started)

This means your child may have already infected other children at daycare before you even knew they were sick. This is why chickenpox spreads so easily in group settings.

How Does Chickenpox Spread?

Chickenpox spreads in two ways:

1. Airborne transmission: The virus spreads through the air when the infected person coughs, sneezes, or breathes. This is the most common route of transmission.
2. Contact transmission: Direct contact with the fluid in the blisters can transmit the virus.

Chickenpox is one of the most contagious childhood diseases. The CDC estimates that 80–90% of susceptible household members will become infected if one family member has chickenpox.

Daycare: When to Keep Your Child Home?

According to the CDC and AAP, the following guidelines apply for daycare:

When your child should stay home:

• From the moment you notice the rash
• As long as the child has fresh blisters (not dried out)
• As long as the child has a fever or is generally unwell

When your child can return:

• When all blisters have crusted over — this usually takes 5–7 days from when the rash started
• The child doesn't need to be completely free of scabs, but there should be no new, fresh blisters
• The child should feel well enough to participate in activities

There is typically no requirement for a doctor's note to return to daycare after chickenpox, but many daycare centers have their own policies. Check with your provider.

What About Siblings?

Siblings who haven't had chickenpox can continue attending daycare or school during the incubation period. They should stay home only when they develop symptoms themselves.

The Course of Illness Day by Day

Here's a typical timeline for chickenpox in children:

Days 1–2: The Prodromal Period (before the rash)

• Mild fever (99.5–101.3°F / 37.5–38.5°C)
• Headache and malaise
• Decreased appetite
• The child may seem more tired than usual

Not all children experience this phase — some develop the rash without warning.

Day 3: The Rash Begins

• Small red spots, often starting on the trunk
• The spots develop into blisters filled with clear fluid
• The rash spreads to the face, arms, and legs
• Intense itching begins

Days 4–6: The Rash Develops

• New blisters appear in waves over 3–5 days
• Older blisters begin to dry out and crust over
• The child may have blisters at various stages simultaneously
• Itching is often worst during this period

Days 7–10: Healing

• No new blisters
• All blisters have crusted over
• Itching gradually subsides
• Overall condition improves
• Scabs fall off over 1–2 weeks

Who Should Be Extra Careful?

Chickenpox is usually mild in healthy children but can be serious for certain groups:

Pregnant Women

Chickenpox during pregnancy can cause complications for both mother and baby. Pregnant women who haven't had chickenpox or been vaccinated should avoid contact with infected individuals. According to the CDC, chickenpox during pregnancy can cause:

• First and second trimester: Risk of congenital varicella syndrome (rare, under 2%)
• Around delivery: Risk of severe varicella in the newborn

Pregnant women who have been exposed to chickenpox should contact their doctor promptly. Treatment with immunoglobulin can be given within 96 hours of exposure.

Newborns Under 4 Weeks

Newborns have an immature immune system and can become seriously ill from chickenpox. If a newborn is exposed to chickenpox, contact a doctor immediately.

Immunocompromised Children

Children receiving immunosuppressive treatment (for example, for cancer or organ transplantation) should be protected from chickenpox exposure. Chickenpox can cause serious complications in this group.

Chickenpox Vaccine — What You Should Know

The chickenpox vaccine (varicella vaccine) is part of the recommended childhood immunization schedule in the United States and many other countries, typically given in two doses — the first at 12–15 months and the second at 4–6 years of age.

Who should get vaccinated?

• All children are recommended to receive the varicella vaccine as part of routine childhood immunizations
• Adults and adolescents who haven't had chickenpox or been vaccinated should also get vaccinated
• The vaccine is especially important for women of childbearing age who haven't had chickenpox and are planning a pregnancy

The vaccine doesn't provide 100% protection

Vaccinated children can in rare cases develop a mild form of chickenpox (breakthrough varicella). These children typically:

• Are less ill
• Have fewer blisters
• Are contagious for a shorter time
• Rarely develop complications

Relieving Symptoms at Home

While your child is home with chickenpox, there's a lot you can do to ease their discomfort:

For itching:

• Lukewarm (not hot) baths or showers
• Calamine lotion on the blisters
• Light, loose-fitting cotton clothing
• Trim fingernails short to prevent scratching
• Antihistamines can help with itching — ask your pharmacist or doctor

For fever and pain:

• Acetaminophen (Tylenol) in the correct dose for your child's age
• Avoid ibuprofen (Advil/Motrin) — health authorities warn against using ibuprofen during chickenpox, as it may increase the risk of serious skin infections

General tips:

• Make sure your child drinks enough fluids
• Offer cold, soft foods if there are blisters in the mouth
• Let the child rest, but don't force bed rest
• Use distraction (movies, books, quiet play) to manage the urge to scratch

When Should You Contact a Doctor?

Most children with chickenpox don't need medical attention, but contact a doctor if:

• The child is under 4 weeks old
• The child has a high fever (over 102.2°F / 39°C) lasting more than 3 days
• The blisters become red, swollen, and warm (signs of bacterial infection)
• The child seems very ill or unusually lethargic
• The child refuses to drink for an extended period
• You are pregnant and have been exposed to chickenpox
• The child is immunocompromised

Can You Get Chickenpox Twice?

Most people who have had chickenpox develop lifelong immunity. It's very rare to get chickenpox twice, though it can occur in people with weakened immune systems.

However, the virus remains dormant in the body after the illness. It can reactivate later in life as shingles (herpes zoster), usually in older adults or immunocompromised individuals.

Infection Control in Practice

To limit the spread within your family and community:

• Keep the sick child home from daycare until all blisters have crusted over
• Avoid contact with pregnant women, newborns, and immunocompromised individuals
• Wash hands thoroughly and frequently
• Change bedding and towels regularly
• Ventilate rooms well — the virus spreads more easily in poorly ventilated spaces

Frequently Asked Questions

How long does chickenpox last in total?

The entire course of illness typically lasts 7–14 days. The rash appears in waves over 3–5 days, and it takes an additional 5–7 days for all blisters to crust over. The scabs fall off over 1–2 weeks after that.

Can my child spread chickenpox before the rash appears?

Yes. The child is contagious from 1–2 days before the rash appears. This is why chickenpox spreads so effectively in daycare centers and schools.

How long does my child need to stay home from daycare?

Your child can return when all blisters have crusted over and they feel well enough. This usually takes 5–7 days from when the rash started.

Can children vaccinated against chickenpox still get sick?

Yes, but very rarely, and if so, they develop a much milder form with fewer blisters and a shorter course of illness.

Is chickenpox dangerous for babies?

For babies over 4 weeks with a normal immune system, chickenpox is usually mild. Newborns under 4 weeks, however, can become seriously ill and should be protected from exposure. Contact a doctor immediately if a newborn is exposed.

What's the difference between chickenpox and shingles?

Both diseases are caused by the varicella-zoster virus. Chickenpox is the initial infection, while shingles is a reactivation of the virus later in life. Shingles causes pain and a rash, but usually only on one side of the body.

This article is based on current guidelines from the CDC and AAP. Last updated March 2026. This article does not replace medical advice — contact your doctor if you have concerns.

Sources:

• CDC - Chickenpox (Varicella)
• AAP - Varicella-Zoster Infections
• CDC - Varicella Vaccine Recommendations