[Pyostomatitis-pyodermatitis vegetans uncovering a case of Crohn disease].

BACKGROUND: Pyostomatitis-pyodermatitis vegetans is an uncommon condition associated with chronic inflammatory bowel disease in 75% of the cases, usually hemorrhagic rectocolitis. CASE REPORT: A 48-year-old man was referred for recent development of pustulous lesions of the lips and buccal mucosa and weight loss. He complained of abdominal pain and intermittent diarrhea which had persisted for more than one year. During the last three months, a pseudotumoral plaque with a pustulous rim had developed over the two distal phalanxes of the right middle finger in association with ungueal lysis and nodular, vegetating and crusted lesions on the lateral aspect of the left arm. Small pustules covered the entire buccal mucosa excepting the tongue and the glans forming a typical snail trace aspect. Bacterial and mycological samples were negative. The histology reports for skin and mucosa were similar: epithelial hyperplasia, intra- and subepithelial granulocyte micro-abscesses and polymorphous infiltration of the superficial derma with numerous neutrophils and eosinophils. There was a discrete interkeratinocytic fluorescence at direct immunofluorescence but indirect immunofluorescence was negative. Anti-desmogleine 1 immunolabeling showed typical normal skin uptake and immunotransfer was negative. Digestive tract endoscopy and histopathology examination of the bowel specimens confirmed the diagnosis of Crohn's disease. Clinical manifestations improved dramatically with prednisone. DISCUSSION: This case of pyostomatitis-pyodermatitis vegetans involved several aspects rarely reported in the literature: a) the cutaneomucosal signs were inaugural; b) the association with Crohn's disease; c) the presence of lesions to the genital mucosa; d) the unusual localization of the inaugural skin manifestations. This clinical entity has now been clearly distinguished from pemphigus vegetans. There was however a long debate on the similar clinical, histological and even immunological expressions. We suggest that pyostomatitis-pyodermatitis vegetans belongs to the spectrum of neutrophilic dermatoses and other authors even propose it is a clinical form of pyoderma gangrenosum.