Chickenpox is an infection caused by the varicella-zoster virus. It causes an itchy rash with small, fluid-filled blisters. Chickenpox is highly contagious to people who haven't had the disease or been vaccinated against it.
Chickenpox is normally a mild disease. But it can be serious and can lead to complications including:
- Bacterial infections of the skin, soft tissues, bones, joints or bloodstream (sepsis)
- Dehydration
- Pneumonia
- Toxic shock syndrome
- Inflammation of the brain (encephalitis)
People who are at higher risk of chickenpox complications include:
- Newborns and infants whose mothers never had chickenpox or the vaccine
- Adolescents and adults
- Pregnant women who haven't had chickenpox
- People who smoke
- People whose immune systems are weakened
- People who are taking steroid medications for another disease or condition, such as asthma
Source:
https://www.mayoclinic.org/diseases-conditions/chickenpox/symptoms-
causes/syc-20351282
