All That Glitters Is Not Pemphigus: Pyodermatitis–pyostomatitis Vegetans Misdiagnosed as IgA Pemphigus for 8 years

Abstract

Pyodermatitis-pyostomatitis vegetans is a rare mucocutaneous dermatosis often associated with gastrointestinal disorders, especially with inflammatory bowel disease. It is clinically characterized by erythematous lesions with multiple pustules and erosions affecting the mucosal surfaces. Cutaneous lesions are characterized by exudative and vegetating plaques affecting frequently the axillae and groins. The clinical diagnosis is supported by histologic findings, whereas immunofluorescence studies are useful to rule out other entities such as pemphigus3. Herein we report the case of a young man who was misdiagnosed as having IgA pemphigus for 8 years due to positive immunofluorescence findings. The clue for the final diagnosis was the diagnosis of a concomitant ulcerative colitis, which prompted us to reconsider his cutaneous disease.

Vegetating Plaques on the Lips

“…8,9 Acanthosis, acantholysis, and suprabasilar clefts are also variably observed. 8 The underlying dermis/lamina propria is characterized by dense lymphocytic, neutrophilic, and eosinophilic infiltrate. 5,8 DIF studies are generally negative.…”

“…Whether such cases are false-positive DIF findings, represent DIF-positive cases of PSV, or represent a pemphigus vegetans variant of IgA pemphigus is controversial. 8,11 What is clear from these cases is that a DIF finding in a case with features consistent with PSV should always prompt a search for related bowel pathology. Pursuing serological confirmation of diseasespecific antibodies may be helpful in further clarifying the relevance of the immunofluorescence findings.…”

“…8 The underlying dermis/lamina propria is characterized by dense lymphocytic, neutrophilic, and eosinophilic infiltrate. 5,8 DIF studies are generally negative. 3,5,10 The differential diagnosis of PSV includes blistering or erosive diseases that involve the oral mucosa, most importantly pemphigus vegetans.…”

“…3,7 About 90% of cases also have peripheral eosinophilia. 3,8 Histologically, PSV is characterized by pseudoepitheliomatous hyperplasia, with intraepithelial microabscesses composed of eosinophils and neutrophils. 8,9 Acanthosis, acantholysis, and suprabasilar clefts are also variably observed.…”

“…3,8 Histologically, PSV is characterized by pseudoepitheliomatous hyperplasia, with intraepithelial microabscesses composed of eosinophils and neutrophils. 8,9 Acanthosis, acantholysis, and suprabasilar clefts are also variably observed. 8 The underlying dermis/lamina propria is characterized by dense lymphocytic, neutrophilic, and eosinophilic infiltrate.…”