An eruption associated with alphavirus infection

Some alphaviruses, e.g. Sindbis, cause an acute febrile illness associated with papular rashes and arthralgia. The diagnosis is usually serological and, hence, the histopathology of the rashes has been poorly elucidated. We report on two patients with rapidly healing eruptions associated with Sindbis virus infection. The histopathology of the rashes showed large, pronounced lymphohistiocytic infiltrates with atypical lymphoid cells around the hair follicles, changes not usually seen in rapidly-healing dermatoses.