Lyme Disease

A 34-year-old man experienced fever and arthralgia several days after appearance of the rash shown here (A). He did not recall being bitten by a tick, as is often the case with persons who contract Lyme disease. The characteristic rash of Lyme disease, erythema migrans—an annular red eruption with a central clear area, such as the lesion shown here on the back of a 71-year-old woman (B)—is observed in 70% or more of patients. Variations include an ecchymosis-like rash, such as the one shown in A; vesicles; and diffuse erythema.

(Case and photograph A courtesy of Steven Luger, MD; photograph B courtesy of Randall H. Suslick, MD.)