Southern tick-associated rash illness: erythema migrans is not always Lyme disease.

Southern tick-associated rash illness (STARI) is a rash occurring after a tick bite. It is a form of erythema migrans, an annular rash with central clearing that is almost identical with the erythema migrans seen in Lyme disease. The etiologic agent is not known but may be a Borrelia species. The tick vector is different in the two diseases. Serious systemic complications are not currently recognized with STARI but treatment with doxycycline is prudent. Differentiating STARI from Lyme disease is discussed.