Volunteer for NIAID-funded clinical studies related to smallpox on ClinicalTrials.gov.
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:
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.
Last Updated August 20, 2008