Chickenpox is a contagious disease caused by the varicella zoster virus . It is more common in children than in adults. A child who has been vaccinated can still develop a mild case of chickenpox, which may go unnoticed by her caregivers. Some signs of chickenpox may include a fever and a headache or stomachache, followed by an outbreak of red spots on the skin that eventually blister. The disease can usually be treated at home, and only in the rare case of a severe outbreak does someone need to seek professional medical treatment.
The chickenpox vaccine was introduced in the United States in 1995. Some vaccinated people sometimes experience a mild case of chickenpox, while most remain immune. Severe chickenpox tends to be more likely in people, including adolescents and adults, who have not been vaccinated. People with certain immune system problems may also have a hard time fighting off such infections.
Infected people are normally contagious for a day or two prior to notice a rash, until the chickenpox blisters have formed. The disease can be spread by breathing, coughing or sneezing, and through direct contact with the blisters once the rash has developed. Some early signs of chickenpox may include a general feeling of illness or lethargy, fever, sore throat, headache, upset stomach, or loss of appetite. However, people with mild chickenpox may not have any obvious symptoms.
Within a few days of noticing their symptoms, a person usually develops a red rash that tends to appear on the face, scalp, or trunk. Over the next few days, the spots turn into fluid-filled blisters that eventually dry out and crust over. New red spots may continue to appear for up to ten days.
Home treatments for mild chickenpox may include medications to treat fever or itching of the blisters. To help soothe the skin, many doctors also advise the use of topical solutions, such as anti-itch creams and lotions, and oatmeal baths. They strongly advise against the administration of aspirin or ibuprofen, due to possible adverse reactions. Acetaminophen, however, has been approved to treat fever and headache.
Common complications of chickenpox can include bacterial infection, either from scratching the blisters or not keeping the area clean. In very rare cases, someone can get chickenpox more than once. This is known as a revolutionary infection . Also, even someone who experiences only mild chickenpox is at risk of developing shingles later in life. The varicella zoster virus can lie dormant in the body until a period of stress causes it to reappear later as Herpes zoster .
Unless they have been vaccinated, adolescents, adults, pregnant women, and people with specific medical conditions are at greatest risk of serious complications. Some birth defects in babies can be caused by chickenpox early in pregnancy. Also, newborns can develop the disease if their mothers contract it a few days after delivery. However, chickenpox in babies younger than 12 months is rare, because antibodies in the mother's uterus usually protect against it.