Chickenpox is an infectious disease caused by the varicella-zoster virus. It is most common in children, also affects adults on occasion. It produces an itchy, blistery rash that typically lasts about a week and is sometimes accompanied by a fever or other symptoms. Chickenpox is usually more severe in adults and very young infants than children.

Chickenpox is normally a mild disease. But it can be serious and can lead to complications. Many cases of chickenpox are mild, but death from this disease can occur.

• The most common complication is bacterial infection of the skin infections which can involve many sites of the body including the skin, bone and blood.
• Chickenpox may also lead to pneumonia.
• Inflammation of the brain (encephalitis) may occur that can be very serious.
• Balance problems related to infection of a specific part of the brain (cerebellitis) may occur.
• A common complication of chickenpox is a transient hepatitis, or inflammation of the liver.
• Chicken pox acquired during pregnancy causes an increase risk of complications to the mother and the infant. The time of infection, during early pregnancy or near delivery, determines the risk to mother and child.