Chickenpox (Varicella)
What is Chickenpox (Varicella)?
Chickenpox is a highly contagious viral infection caused by the varicella zoster virus. It creates an itchy rash with fluid-filled blisters that spreads across the body. Most people get chickenpox during childhood, but adults can catch it too.
Once you recover from chickenpox, the virus stays dormant in your nerve cells. Your immune system keeps it in check for life in most cases. The same virus can reactivate later as shingles, usually in adults over 50. This happens when your immune system weakens with age or stress.
Chickenpox used to infect millions of children each year before the vaccine became available in 1995. Vaccination has reduced cases by more than 90% in the United States. Most vaccinated people never get chickenpox, and those who do usually have milder symptoms.
Symptoms
Chickenpox symptoms usually appear 10 to 21 days after exposure to the virus.
- Itchy red rash that starts on the chest, back, and face, then spreads
- Fluid-filled blisters that break open and form crusts
- Fever, usually 101 to 102 degrees Fahrenheit
- Headache and general feeling of being unwell
- Loss of appetite
- Tiredness and fatigue
- Spots in different stages, with new blisters appearing as old ones crust over
The rash typically lasts 5 to 7 days. Some people may have only a few spots, while others develop hundreds. Vaccinated individuals who still get chickenpox often have fewer than 50 spots and minimal fever.
Concerned about Chickenpox (Varicella)? Check your levels.
Screen for 1,200+ health conditions
Causes and risk factors
Chickenpox spreads when someone breathes in virus particles from an infected person's cough or sneeze. You can also catch it by touching the fluid from chickenpox blisters. The virus is so contagious that 90% of unvaccinated people who live with someone infected will catch it. People with chickenpox can spread it from 1 to 2 days before the rash appears until all blisters have crusted over.
Your risk increases if you have never had chickenpox or the vaccine. Newborns, pregnant women, and people with weakened immune systems face higher risks of severe complications. Adults who get chickenpox often have more serious symptoms than children. Stress, poor nutrition, and lack of sleep can make it harder for your immune system to fight off the virus.
How it's diagnosed
Doctors usually diagnose chickenpox by looking at the characteristic rash and asking about exposure history. The pattern of itchy blisters in different stages is easy to recognize. Blood tests can check for varicella zoster virus antibodies to confirm if you had a past infection or have immunity. This antibody test looks for IgG antibodies that remain in your blood after infection or vaccination.
Testing for varicella immunity helps determine if you need vaccination or are at risk for infection. Healthcare workers, teachers, and people planning to become pregnant often get tested. Talk to your doctor about specialized testing options if you need to verify your immunity status or diagnose an active infection.
Treatment options
- Rest at home to help your body fight the infection
- Take lukewarm baths with colloidal oatmeal to soothe itching
- Apply calamine lotion to reduce skin irritation
- Use acetaminophen for fever, never aspirin in children due to Reye syndrome risk
- Keep fingernails trimmed short to prevent scratching and scarring
- Wear loose cotton clothing to reduce skin irritation
- Drink plenty of fluids to stay hydrated
- Take antihistamines to help control itching at night
- Antiviral medications like acyclovir for high-risk patients if started within 24 hours
- See a doctor immediately if you develop severe headache, stiff neck, or breathing problems
Frequently asked questions
The chickenpox rash typically lasts 5 to 7 days from start to finish. New spots continue to appear for 4 to 5 days, while older spots crust over. Most people feel completely better within 2 weeks. You stop being contagious once all blisters have formed crusts.
Getting chickenpox twice is extremely rare but possible. Most people develop lifelong immunity after one infection. If you had a very mild case the first time, your immune response might not be strong enough to prevent a second infection. People with weakened immune systems have a slightly higher risk of repeat infections.
Children should get two doses of the varicella vaccine, the first at 12 to 15 months and the second at 4 to 6 years. Adults who never had chickenpox or the vaccine should get two doses 4 to 8 weeks apart. Healthcare workers, teachers, and people who live with someone with a weakened immune system should prioritize vaccination.
Adults face higher risks of serious complications from chickenpox than children. Pneumonia, brain inflammation, and bacterial skin infections occur more often in adults. Pregnant women can develop severe disease and may pass the virus to their baby. Adults with chickenpox should contact their doctor, especially if symptoms worsen or fever persists beyond 4 days.
No, you should stay home until all blisters have crusted over, usually 5 to 7 days after the rash starts. You are contagious from 1 to 2 days before the rash appears until all spots have scabs. Going out during this time puts others at risk, especially pregnant women, newborns, and people with weak immune systems.
Shingles is caused by the same virus that causes chickenpox. After chickenpox heals, the virus stays dormant in your nerve cells for life. It can reactivate decades later as shingles, causing a painful rash along one side of your body. About 1 in 3 people who had chickenpox will develop shingles, usually after age 50.
You are likely immune if you had chickenpox as a child or received two doses of the varicella vaccine. A blood test can check for varicella zoster virus antibodies to confirm immunity. Most people born before 1980 in the United States had chickenpox during childhood. Talk to your doctor about antibody testing if you are unsure about your immunity status.
Bacterial skin infections from scratching are the most common complication. More serious problems include pneumonia, brain inflammation, bleeding problems, and bloodstream infections. Pregnant women, newborns, adults, and people with weakened immune systems face the highest risk. Seek immediate medical care if you develop trouble breathing, severe headache, stiff neck, or confusion.
Yes, lukewarm baths can help relieve itching and keep skin clean. Add colloidal oatmeal or baking soda to the water for extra soothing relief. Avoid hot water, which can make itching worse. Pat your skin dry gently with a towel instead of rubbing.
Yes, pregnant women who never had chickenpox or the vaccine should avoid anyone with the infection. Chickenpox during pregnancy can cause serious complications for both mother and baby. If exposed, pregnant women should contact their doctor immediately. A medication called varicella zoster immune globulin can help prevent or reduce severity if given within 10 days of exposure.