Chickenpox is the primary infection caused by the varicella-zoster virus. It is an acute, highly infectious disease most commonly seen in children under 10 years old.
Chickenpox is usually a mild, self-limiting illness and most healthy children recover with no complications. Adults tend to suffer more severe disease than children. After recovery from chickenpox the virus stays dormant (inactive) in the nerves near the spine. Years later the virus can become active again and cause herpes zoster, which is also known as shingles.
Chickenpox is highly contagious, infecting up to 90% of non-immune people who are exposed to the disease. The incubation period (the time from becoming infected until symptoms appear) ranges from 10 to 21 days although is usually from 14-16 days. The most common symptoms of chickenpox are an itchy rash with small blisters, fever, tiredness, headache, and loss of appetite. The rash usually develops on the scalp and body, and then spreads to the face, arms, and legs.
Susceptible individuals who have been in contact with a person with chickenpox should be considered potentially infectious from the 10th to the 21st day after exposure.
Transmission occurs from person to person by direct contact with persons with either varicella or herpes zoster (shingles), inhalation of aerosols from vesicular fluid of skin lesions of persons with varicella or zoster, and through infected respiratory secretions that also may be aerosolized.
Recovery from primary varicella infection usually results in lifetime immunity. In otherwise healthy persons, a second occurrence of chickenpox is not common, but it can happen, particularly in immunocompromised persons.
Chickenpox
