n. an acute infectious virus disease causing high fever and a rash that scars the skin. It is transmitted chiefly by direct contact with a patient. Symptoms commence 8–18 days after exposure and include headache, backache, high fever, and vomiting. On the third day, as the fever subsides, red spots appear on the face and spread to the trunk and extremities. Over the next 8–9 days all the spots (macules) change to pimples (papules), then to pea-sized blisters that are at first watery (vesicles) but soon become pus-filled (pustules). The fever returns, often causing delirium. On the eleventh or twelfth day the rash and fever abate. Scabs formed by drying out of pustules fall off 7–20 days later, leaving permanent scars. The patient remains infectious until all scabs have been shed. Most patients recover but serious complications, such as nephritis or pneumonia, may develop. Treatment with thiosemicarbazone is effective. An attack usually confers immunity; immunization against smallpox has now totally eradicated the disease. Medical name: variola. See also alastrim, cowpox.
Subjects: Medicine and health