Early lesion of palisaded neutrophilic granulomatous dermatitis in ulcerative colitis.

Palisaded neutrophilic granulomatous dermatitis (PNGD) is a rare clinical entity of unknown cause. It often coexists with various autoimmune or immunoreactive systemic diseases, and thus it has been reported under multiple names. We describe a patient with quiescent ulcerative colitis, who presented with recurrent small tender papules, nodules and erythematous plaques, located mainly on her hands, together with finger swelling and polyarthralgia. The histopathologic picture indicated an early stage of PNGD with focal degeneration of collagen fibers but without distinct granuloma formation. The differentiation from neutrophilic dermatoses was necessary because of dense and diffuse infiltration of neutrophils with leukocytoclastic debris throughout the dermis, and the association of ulcerative colitis. Dapsone monotherapy was effective in improving the clinical symptoms. PNGD is only rarely associated with ulcerative colitis, and this case suggests that the concept of PNGD, especially in its early stages, might be considered in the wide spectrum of neutrophilic dermatoses.