Chickenpox Incubation: How Long?

Chickenpox is a very common infection in children and can affect adults as well. It usually causes an itchy blistering rash and a mild flu like illness.nhs.uk

The time between catching the virus and noticing the first symptoms is called the incubation period.

For chickenpox this incubation period is usually around 10 to 21 days after contact with someone who has the infection.nhs.uk+2UHCW+2

Families in South Ealing, Ealing, Acton, Hanwell, Brentford and the wider West London area often want to know what this means in everyday life.

What does “incubation period” mean

The incubation period is the time from when a virus enters the body to when the first symptoms start.

There are no visible signs during this early phase and people usually feel well.

Incubation matters because it helps you work out when symptoms might appear after a known contact with chickenpox.

It also helps to judge when you or your child might be contagious and when it is safer to mix with others.nhs.uk+1

How long is the chickenpox incubation period

Most people who catch chickenpox develop symptoms between 10 and 21 days after being exposed to the virus.nhs.uk+2UHCW+2

Many cases start nearer the middle of that window, often around 14 to 16 days after contact.

The exact timing can vary. Children, adults and people with weaker immune systems can all follow the same general pattern, although illness may be more severe in some groups.nhs.uk+1

Some medicines that affect the immune system can also influence how the illness appears. If you or your child take such medicines, medical advice is important.Sheffield Children's NHS+1

How do you catch chickenpox

Chickenpox spreads very easily between people.nhs.uk+1

You can catch it when a person with chickenpox coughs or sneezes and you breathe in tiny droplets carrying the virus.

You can also catch it through close face to face contact or by touching the fluid from chickenpox blisters.nhs.uk+2UHCW+2

Because it spreads so efficiently, households, nurseries, schools and offices in areas like South Ealing and surrounding neighbourhoods often see several cases at the same time.

When is someone with chickenpox most contagious

A person with chickenpox can pass the virus to others one to two days before the rash appears.UHCW+2Bupa+2

They remain contagious until all spots have crusted over, which usually takes about five to seven days after the rash first appears.UHCW+2Public Health Wales+2

For families this means a child may have shared the virus with siblings or classmates before anyone realised they were ill.

It also means children should stay away from school or nursery until every spot has formed a crust and no new spots are appearing.nhs.uk+1

Timeline of symptoms after exposure

Days 0 to 7 after exposure

Most people feel completely well in the first week after contact.

There are usually no signs of illness and ordinary activities can continue as normal.

Days 7 to 10 and beyond

Early symptoms can include a mild fever, feeling tired, headache and loss of appetite.nhs.uk+1

These symptoms may be quite mild in children but can be more noticeable in adults.

When the rash appears

The classic chickenpox rash usually starts on the chest, back or face before spreading to other areas, including inside the mouth.nhs.uk+1

Spots often begin as small red bumps, then turn into fluid filled blisters.

Over a few days the blisters break and form crusts. New crops of spots can appear while older ones are already scabbing.

When the spots start to heal

Spots gradually dry, crust and scab over.

Children can usually return to school or nursery once every spot has crusted and there are no fresh spots, as they are then much less likely to pass the virus on.nhs.uk+1

Chickenpox incubation in different groups

Children

Chickenpox is most common in younger children.

The incubation period is usually the same as in adults but symptoms are often milder and recovery is usually quick.nhs.uk+1 

Adults

Adults tend to have the same incubation period but can experience a higher fever and more spots.nhs.uk+1 

Complications, such as chest infection or problems affecting the brain, are more likely in adults, especially in those who smoke or have other long term conditions.nhs.uk+1 

Anyone who feels very unwell or short of breath should seek urgent medical advice.

Pregnant women, newborns and people with weak immune systems

Pregnant women, very young babies and people with a weakened immune system are at higher risk from chickenpox.nhs.uk+2CDC+2 

If someone in these groups has been in close contact with chickenpox, they should contact a doctor, midwife or specialist urgently, even if they feel well.

What to do if you think you have been exposed

If you know you or your child have spent time with someone who has chickenpox, watch for symptoms during the 10 to 21 day incubation window.nhs.uk+1 

Try to avoid close contact with pregnant women, newborn babies and people who have weaker immune systems in this period, especially in shared homes and workplaces.Public Health Wales+1 

A pharmacist at South Ealing Pharmacy can advise on symptom monitoring, comfort measures and when to seek further help.

If you are very unwell, pregnant, or have a long term condition that affects the immune system, contact your GP or NHS 111.

Can you prevent chickenpox after exposure

In some higher risk situations, such as certain pregnant women or people with severely weakened immune systems, doctors may consider specific treatments or a vaccine after confirmed exposure.nhs.uk+2CDC+2 

These decisions are made case by case by hospital teams or specialist services.

Local families who are not eligible for free vaccination can access private chickenpox vaccination at some community clinics, including services like the chickenpox vaccine offered by South Ealing Pharmacy.nhs.uk+1 

If you think you or your child might benefit from vaccination, speak with a pharmacist or your GP as early as possible.

Caring for chickenpox at home once it appears

Most cases can be managed at home with simple comfort care.

Helpful steps include:

• Offering plenty of fluids to prevent dehydration
• Using soothing preparations recommended by a pharmacist for itchy skin
• Using loose, comfortable clothing to reduce irritation

Paracetamol can be used for fever, following the instructions on the pack, but aspirin must not be given to children with chickenpox.

Keep fingernails short and clean. Cotton mittens on young children at night can help reduce scratching and lower the chance of scarring or infection.

When to seek urgent medical help

Contact a doctor, NHS 111 or emergency services urgently if someone with suspected or confirmed chickenpox has any of the following warning signs:

• Difficulty breathing, chest pain or fast breathing
• Severe headache, confusion, neck stiffness or dislike of bright light
• Very high temperature or unusual drowsiness, floppiness or difficulty waking
• A rash that looks infected, with spreading redness, oozing fluid or severe pain
• Rash that suddenly worsens, especially in adults or in high risk groups

Chickenpox incubation FAQs

If my child has been exposed, how long do we need to watch for spots?

Watch for symptoms for 21 days after the last contact with the person who has chickenpox.

Can my child go to school if they have been exposed but have no symptoms?

Yes, children can usually attend school or nursery while well and without a rash, unless a health professional advises otherwise.nhs.uk

Can you catch chickenpox twice?

Most people only get chickenpox once because the body builds long lasting immunity. A second episode is uncommon but can happen in rare cases.

If I had chickenpox as a child, can I still pass it on to others?

You should not spread chickenpox to others unless you develop shingles later in life, which can pass the virus to people who have never had chickenpox.

What if the spots do not appear but my child had a fever?

Fever alone is common in many childhood illnesses. If spots have not appeared after 21 days from contact, chickenpox becomes less likely, but you can ask a pharmacist or GP for individual advice.

Summary

Chickenpox incubation usually lasts around 10 to 21 days from exposure to the first symptoms. People are most contagious from one to two days before the rash until every spot has crusted.

Families across South Ealing, Ealing, Acton, Hanwell, Brentford and West London can speak to South Ealing Pharmacy for practical guidance on symptom monitoring, comfort care and vaccination.

✅ You can book an appointment online, visit the pharmacy in person or call for advice from the team.

If you are worried about chickenpox exposure or symptoms, speak to a pharmacist or other healthcare professional for personalised advice.

References

• NHS, Chickenpox
• NHS, Chickenpox vaccine
• Public Health Wales, Chickenpox
• Sheffield Children’s NHS Foundation Trust, Chickenpox and herpes zoster guidance
• Bupa, Chickenpox symptoms, diagnosis and treatment
• Centers for Disease Control and Prevention, Clinical overview of chickenpox