Symptoms
Symptoms of smallpox infection usually appear within 10 to 12 days after exposure to the virus. The first symptoms of smallpox may be difficult to distinguish from other flu-like illnesses and include
- High fever
- Fatigue
- Malaise
- Headache
- Backache
- Rash
A characteristic rash, most prominent on the face, arms, and legs, follows 2 to 3 days after the first symptoms. The rash starts with flat red lesions (sores) that develop at the same rate. After a few days, the lesions become filled with pus. They begin to crust early in the second week. Scabs develop and then separate and fall off after about 3 weeks.