MODEL RELEASED. Chickenpox. Boy, aged 3, suffering from chickenpox infection, with calamine lotion applied to his face. Chickenpox (also called varicella) is an infectious disease of childhood characterised by a rash and slight fever. The virus that causes chickenpox, herpesvirus, is transmitted by airborne droplets. About 2 weeks after infection, a mild fever develops followed by an itchy rash of dark red pimples which spread throughout the body. The pimples turn into blisters and then scabs which drop off after about 12 days. The only treatment is bed rest and the application of calamine lotion to relieve the itchiness of the rash.