Clinical Effects of Smallpox: Pathophysiology of Natural Infection

Prodrome (pre-eruptive stage)

The prodrome, or pre-eruptive stage, usually lasts between one to four days. (22:V1:3) The pre-eruptive stage of the illness begins abruptly with fever, malaise, headache, muscle pain, prostration and often nausea and vomiting and backache. (19:5) The temperature usually rises to at least 101¾ F, and is often higher. A severe febrile prodrome prior to rash onset is characteristic of smallpox, and helps differentiate it from many other causes of rash illness. (19:5) 

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