In pyodermatitis-pyostomatitis vegetans annular pustular cutaneous lesions may precede, accompany, or follow the usually extensive vegetating oral disease. Sometimes only cutaneous or only oral lesions occur and previously have been described as separate entities. Clinical, histopathologic, and immunopathologic evidence clearly indicates this is one disease and suggests that it is distinct from pemphigus vegetans. The association between pyodermatitis-pyostomatitis vegetans and inflammatory bowel disease, most commonly ulcerative colitis, has been amply confirmed. Pyodermatitis-pyostomatitis vegetans should be considered a marker for inflammatory bowel disease.