Palisaded neutrophilic granulomatous dermatitis in rheumatoid arthritis
Palisaded neutrophilic granulomatous dermatitis (PNGD) is an entity that has not been clearly defined either clinically or histopathologically. It is seen in patients with rheumatoid arthritis and other connective tissue diseases. In the past, many cases of PNGD have been described under several different names including palisaded neutrophilic and granulomatous dermatitis, linear subcutaneous bands, interstitial granulomatous dermatitis with cutaneous cords and arthritis, rheumatoid papules, and Churg-Strauss granuloma. We report 7 additional cases of PNGD. Clinically, 6 patients presented with erythematous to violaceous plaques, papules, and nodules on multiple body sites; one presented with subcutaneous linear bands on the shoulder. Five had rheumatoid arthritis; one had adult-onset Still's disease; and one showed clinical signs of rheumatoid arthritis, although serologically the rheumatoid factor was negative. On histologic examination, a spectrum of changes was observed ranging from urticaria-like infiltrates to leukocytoclastic vasculitis and granuloma annulare with neutrophils. We report these cases to expand the histologic spectrum of this entity and to further delineate the different forms of clinical presentation.