infections
Smallpox
Symptoms of Smallpox
Symptoms of the severe form usually begin 7 to 17 days after infection. Infected people develop fever, headache, and backache and feel extremely ill. They may have severe abdominal pain and become delirious. After 2 or 3 days, a rash of flat, red spots develops in the mouth and on the face. Shortly thereafter, it spreads to the trunk and legs, then the hands and feet. People are contagious only after the rash has started and are most contagious for the first 7 to 10 days after the rash appears. After 1 or 2 days, the spots turn into blisters, which fill with pus (forming pustules). After 8 or 9 days, the pustules become crusted. The lungs, brain, and/or bone may become infected. About 30% of people with smallpox die, usually in the second week of the disease. Some of the survivors are left with large, disfiguring scars. In a few people with the severe form, the initial symptoms develop more quickly and are more intense. One rare type, called hemorrhagic smallpox, causes bleeding. After a few days, bleeding occurs in the skin, mucous membranes, and gastrointestinal tract. Almost all people with hemorrhagic smallpox die in 5 or 6 days. In the less severe form, symptoms are similar but much less severe. The rash is much less extensive, and fewer than 1% of people die. 