A 58-year-old man had a 9-month history of tender petechiae on the hands, feet, ankle, thigh, and knee (Figure 1). He also reported a history of psoriasis. The results of workup for systemic vasculitis, including urinalysis; erythrocyte sedimentation rate; C-reactive protein; complete blood cell count; basic metabolic panel; liver function tests; anti-DNA tests; total hemolytic complement; complement profile; partial thromboplastin time; prothrombin time; rheumatoid factor; and antineutrophil cytoplasmic, ribonucleoprotein, Smith, Ro, and La antibodies testing, were negative. The antinuclear antibody test result was positive to a dilution of 1:160. The patient subsequently developed mildly pruritic, erythematous macules, pustules, and crusted papules ranging from 2 to 6 mm in diameter on the bilateral aspect of the knees, elbows, forearms, scalp, and neck (Figure 2). The patient's review of systems revealed episodes of loose stool, which had occurred several times a week since adolescence.