A person with chickenpox is contagious from 1-2 days before the rash appears until all blisters have formed scabs.
Chickenpox commonly starts without warning or with a mild fever and discomfort (Longe 2006).
Today, an easier course if available with the availability of a vaccine that is highly effective for preventing chickenpox, and especially for the most severe cases.
Shingles, a reactivation of chickenpox, may also be a source of the virus for susceptible children and adults.
The initial infection with the varicella-zoster virus (the primary VZV infection) results in chickenpox (varicella), which may rarely result in complications including VZV encephalitis or pneumonia.
Chickenpox infection tends to be milder the younger a child is and symptomatic treatment, with a little sodium bicarbonate in baths or antihistamine medication to ease itching (Somekh et al.
Following primary infection, there is usually lifelong protective immunity from further episodes of chickenpox.
One history of medicine book credits Giovanni Filippo (1510–1580) of Palermo with the first description of varicella (chickenpox).
Second infections with chickenpox occur in immunocompetent individuals, but are uncommon.
The chickenpox lesions (blisters) start as a 2–4 mm red papule, which develops an irregular outline (rose petal).
Chickens are exposed to artificial light cycles to stimulate egg production year-round.
Later, in 1767, a physician named William Heberden, also from England, was the first physician to clearly demonstrate that chickenpox was different from smallpox.
Chickenpox is caused by the varicella-zoster virus (VZV), also known as human herpes virus 3 (HHV-3), one of the eight herpes viruses known to affect humans.
Chickenpox is a highly contagious disease that spreads from person to person by direct contact or through the air from an infected person's coughing or sneezing.
Recurrent chickenpox, commonly known as shingles, is fairly rare but more likely in people with compromised immune systems.
Pregnant women not known to be immune and who come into contact with chickenpox may need urgent treatment as the virus can cause serious problems for the baby.