A 32-year-old man presented with a 6-week history of 3 pruritic skin lesions on his lower back area and thigh. The lesions were temporally related to a vacation that he had taken in Costa Rica. He did not recall having been bitten by an insect while he was traveling. A review of systems revealed no abnormalities. The patient's medical history included asthma and seasonal allergies.
Initial examination revealed three 1-cm firm nodules with central erosion surrounded by a localized area of eczematous dermatitis. There were 2 lesions on the left lower back area and 1 on the posterior aspect of the upper part of the thigh. After intralesional steroid injection, the nodules regressed, and diffuse erythema, shiny papules, and weeping erosions developed 1 month later (Figure 1). The physical examination also demonstrated a nontender, multinodular cord on the left chest wall and flank, a palpable left inguinal node, and edema of the left lower extremity. Biopsy specimens were obtained for histologic examination and culture (Figure 2).