Chickenpox
Chickenpox, or chicken pox, also known as varicella, is a highly contagious, vaccine-preventable disease caused by the initial infection with varicella zoster virus (VZV), a member of the herpesvirus family.[3][5]
The disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab over.[1]
It usually starts on the chest, back, and face.[1]
It then spreads to the rest of the body.[1]
The rash and other symptoms, such as fever, tiredness, and headaches, usually last five to seven days.[1]
Complications may occasionally include pneumonia, inflammation of the brain, and bacterial skin infections.[7]
The disease is usually more severe in adults than in children.[8]
Chickenpox is an airborne disease which easily spreads via human-to-human transmission, typically through the coughs and sneezes of an infected person.[5]
The incubation period is 10–21 days, after which the characteristic rash appears.[2] It may be spread from one to two days before the rash appears until all lesions have crusted over.[5]
It may also spread through contact with the blisters.[5]
Those with shingles may spread chickenpox to those who are not immune through contact with the blisters.[5]
The disease can usually be diagnosed based on the presenting symptom;[9] however, in unusual cases it may be confirmed by polymerase chain reaction (PCR) testing of the blister fluid or scabs.[8]
Testing for antibodies may be done to determine if a person is immune.[8]
People usually only get chickenpox once.[5]