Abstract: A 55-year-old male presented with erythematous plaques and scales on the extensor surface of extremities for 5 years. He has a history of ankylosing spondylitis (AS) for 10 years.. The biopsy showed granulomatous?nodules in the dermis, and some histiocytes, lymphocytes, neutrophils in a pattern of palisading arrangement. Antinuclear antibody, anti-SS-B, anti-SS-A and anti–double-stranded DNA were negative. HLA-B27 was positive. The diagnosis of palisaded neutrophilic granulomatous dermatitis companied with ankylosing spondylitis was made.

Key words: palisaded neutrophilic granulomatous dermatitis, ankylosing spondylitis