Chickenpox, Varicella
Varicella is a disease caused by infection with the varicella zoster virus, which causes a very itchy skin rash of blister-like lesions, covering the entire body but usually more concentrated on the face, scalp, and trunk. Most, but not all, infected individuals have a fever, which develops just before or when the rash appears. If exposed, persons who have been vaccinated against the disease may get a milder illness, with less severe rash (sometimes involving only a few red bumps that look similar to insect bites) and mild or no fever.
Some complications that can occur due to the disease are a bacterial infection of the skin, swelling of the brain, and pneumonia. Adolescents and adults are more at risk for severe disease.
This disease is spread by coughing and sneezing (highly contagious), by direct contact, and by the virus becoming airborne from a skin lesion.