Variola Information

Concern for the use of smallpox virus as a bioterrorist weapon has led to the reintroduction of vaccination in some segments of the population (first responders and the military).

Differential Diagnosis of Variola

Smallpox and vaccinia are to be distinguished from generalized varicella zoster virus infection or generalized herpes simplex. The latter two viral infections are not associated with a severe febrile prodrome. Lesions are at various stages at each anatomic site. Varicella usually appears in waves or crops. Multiple palm and sole lesions are common in variola and uncommon in generalized varicella-zoster and herpes simplex infection.

Symptom of Variola

The incubation period for variola averages 12 days (7-17 days). The prodrome begins with abrupt onset of high fever, severe headaches, and backaches. At this stage, the infected person appears quite ill. The infectious phase begins with the appearance of an enanthem, followed in 1-2 days by a skin eruption. The lesions begin as macules, progressing to papules, then pustules, and finally crusts over 14-18 days. The face and distal extremities are favored. The face is affected first, followed by the upper extremities, then the lower extremities and trunk, completely evolving over 1 week. Lesions are relatively monomorphous, especially in each anatomic region.

Variola Home Treatment

There is no specific and proven antiviral therapy for vaccinia or variola. Vaccinia immune globulin is used to treat eczema vaccinatum and progressive vaccinia. Cidofovir may have some activity against these poxviruses.