Usefulness of a Simple Immunohistochemical Staining Technique to Differentiate Anti-p200 Pemphigoid From Other Autoimmune Blistering Diseases: A Report of 2 Cases

Anti-p200 pemphigoid is a rare autoimmune subepidermal blistering disease characterized by the presence of circulating immunoglobulin G antibodies directed against laminin gamma-1, a 200-kDa protein located in the lamina lucida of the basement membrane. We review the clinical, histopathological and immunological characteristics of the first 2 cases described in Spain. Anti-p200 pemphigoid shares histopathological and immunopathological findings with epidermolysis bullosa acquisita, the main entity in the differential diagnosis. However, its management follows the same guidelines as those used for bullous pemphigoid. The diagnosis is confirmed by immunoblotting, which is a complex technique available in few centers. We propose the immunohistochemical detection of collagen type IV on the floor of the blister, combined with standard immunofluorescence techniques, as a simple, accessible alternative to differentiate anti-p200 pemphigoid from epidermolysis bullosa acquisita.

Localized pemphigus foliaceus with unilateral facial involvement

Pemphigus foliaceus is a superficial vesiculobullous disease that typically presents with widespread lesions. Localized presentations are less frequent, and they typically occur in middle-aged patients, following exposure to topical medications, and later on, become more disseminated. We present a case of a 19-year-old female with a localized presentation of pemphigus foliaceus unrelated to previous topical medications, that was a diagnostic and therapeutically challenging case. We also discuss the literature on localized cases, differences in presentations and responses to various treatment modalities.