Cutaneous palisaded allergic granuloma associated with rheumatic disease

A 62-year-old man presented with a 5-year history of symmetric, hard papules on both of his elbows. These lesions were completely asymptomatic, but they were of cosmetic concern to the patient. Summer and trauma reportedly exacerbated the appearance of new papules, which tended to evolve spontaneously, harden, and subsequently ulcerate. The patient's main medical problem was a long-standing history of rheumatoid arthritis treated with low-dose oral prednisone. Physical examination revealed multiple scattered papules bilaterally on the extensor surfaces of the forearms. These were 2-10 mm in size, red to violaceous, and hard. Some of the lesions had ulcerated centers or slight umbilication (Fig. 1A,B). Histologic examination revealed several granulomas in the mid- to deep dermis with central basophilic fibrillar collagen necrosis (Fig. 2A). The necrotic areas were interspersed with bands of neutrophils, lymphocytes, and leukocytoclastic debris. The periphery of these basophilic granulomas was lined by palisading histiocytes (Fig. 2B).