Chickenpox is normally a mild disease. But it can be serious and can lead to complications, especially in high-risk people. Complications include:

  • Bacterial infections of the skin, soft tissues, bones, joints or bloodstream (sepsis)
  • Pneumonia
  • Inflammation of the brain (encephalitis)
  • Toxic shock syndrome
  • Reye's syndrome for people who take aspirin during chickenpox

Who's at risk?

Those at high risk of having complications from chickenpox include:

  • Newborns and infants whose mothers never had chickenpox or the vaccine
  • Adults
  • Pregnant women who haven't had chickenpox
  • People whose immune systems are impaired by medication, such as chemotherapy, or another disease, such as cancer or HIV
  • People who are taking steroid medications for another disease or condition, such as children with asthma
  • People taking drugs that suppress their immune systems

Chickenpox and pregnancy

Other complications of chickenpox affect pregnant women. Chickenpox early in pregnancy can result in a variety of problems in a newborn, including low birth weight and birth defects, such as limb abnormalities. A greater threat to a baby occurs when the mother develops chickenpox in the week before birth. Then it can cause a serious, life-threatening infection in a newborn.

If you're pregnant and not immune to chickenpox, talk to your doctor about the risks to you and your unborn child.

Chickenpox and shingles

If you've had chickenpox, you're at risk of another disease caused by the varicella-zoster virus called shingles. After a chickenpox infection, some of the varicella-zoster virus may remain in your nerve cells. Many years later, the virus can reactivate and resurface as shingles — a painful band of short-lived blisters. The virus is more likely to reappear in older adults and people with weakened immune systems.

Shingles can lead to its own complication — a condition in which the pain of shingles persists long after the blisters disappear. This complication, called postherpetic neuralgia, can be severe.

A shingles vaccine (Zostavax) is available and is recommended for adults age 60 and older who have had chickenpox.

Mar. 26, 2013