Peristomal Punctate Pemphigus.

Cutaneous reactions surrounding abdominal stoma sites are typically irritant, allergic, infectious, traumatic or pathergic in etiology. Pemphigus, which encompasses a group of vesiculobullous autoimmune skin disorders, is seldom encountered as a peristomal dermatosis. Direct immunofluorescence (DIF) studies of pemphigus generally show continuous intercellular net-like depositions of IgG. However, punctate or dot-like intercellular deposition of IgG can also be seen in cases of pemphigus. The punctuate pattern is underreported in the literature and little is known about its implication. We describe a case of a 58-year-old Caucasian man with a history of bowel obstruction, status postcolostomy, who presented with a sharply demarcated, erythematous, crusted plaque surrounding his abdominal stoma. The patient endorsed persistent pruritus. A punch biopsy of the lesion was performed for clinical suspicion of fungal infection versus irritant dermatitis. Histopathology revealed a predominantly subcorneal acantholytic dermatitis. Periodic acid-Schiff with diastase and Grocott methenamine silver histochemical stains were negative for fungi. DIF was positive for IgG and C3 detected in a punctate intercellular pattern. In conjunction with the patient's clinical presentation and DIF, a diagnosis of peristomal pemphigus foliaceous was rendered. Herein, we describe a case of punctate pemphigus presenting as a peristomal dermatosis and include a review of the literature to raise awareness of this phenomenon.