Erythematous Papular Rash on the Upper Back Area—Quiz Case

Abstract

A 56-year-old white man living in San Antonio, Tex, presented with a 1-week history of edema and tender papules on his hands at the beginning of February. He had worn gloves while working outdoors the previous weekend, during which time the temperatures ranged from 6.1°C to 13.3°C, with a cold front bringing above-normal rainfall and high humidity. The patient had grown up in Montana and had a personal history of frostbite. He denied constitutional symptoms. Physical examination revealed multiple tender, erythematous papules, with associated edema, over the dorsal and palmar aspects of the index, middle, and ring fingers of the left hand (Figure 1). There was less involvement of his right hand. Several papules were purpuric. A punch biopsy specimen was obtained from a representative lesion (Figure 2 and Figure 3). A gram stain and bacterial culture were negative for organisms. The results of a complete blood cell count, coagulation studies, and serum protein electrophoresis, as well as levels of antinuclear antibodies, cryoglobulins, cold agglutinins, and SSA and SSB antibodies, were within normal limits. What is your diagnosis?