A 28-year-old man presented with multiple skin lesions and a painful swollen right ankle. He had first noticed a purulent blister on his right knee about two weeks earlier. This lasted for several days, and then similar skin lesions developed on his left leg, the bilateral palmar surfaces of his hands, and the plantar surfaces of his feet. Right ankle pain also began about two weeks earlier and improved enough to permit partial weight-bearing. The patient had a cough and subjective fevers lasting for 48 hours but no other symptoms, including oral or genital lesions, vision changes, eye pain, pain with urination, or penile discharge. He denied history of sexually transmitted infections or new sexual contacts.

On physical examination, his vital signs were normal. A painful papular lesion with central ulceration was noted on his right knee (Figure 1). Pustules were present on his left palm (Figure 2) and left posterior leg, with tender subcutaneous red nodules on the sole of his left foot. The lesions were 5 to 10 mm in diameter, were nonblanchable, and had no purulence or bleeding. No lesions were noted on his tongue, gums, or soft or hard palate. His right foot was slightly swollen but showed no ecchymosis, erythema, or fluctuance. He had tenderness over the lateral subtalar joint and along the midfoot.