Broad histopathologic patterns of non-glabrous skin and glabrous skin from patients with a new variant of endemic pemphigus foliaceus-part 1.

A prospective, controlled epidemiologic survey performed in El Bagre, Colombia revealed a new variant of endemic pemphigus disease, occurring in a gold mining region. The disease resembled Senear-Usher syndrome, and occurred in an endemic fashion. The aim of this study is to describe the most frequent histopathologic patterns in non-glabrous skin and in glabrous skin observed in these patients, and their clinical correlation. The study was performed on non-glabrous skin biopsies of 30 patients from the dominantly clinical affected areas (either on the chest, arms or face). Simultaneously, biopsies from the palms were obtained in 10 randomly chosen patients of the 30 total patients. The specimens were examined following hematoxylin and eosin (H&E) staining. The most common blisters observed were subcorneal, although in some cases intraspinous and subepidermal blisters were visualized. Our results showed a very heterogeneous pattern of histopathologic patterns in non-glabrous skin, which seemed to correlate with the clinical features. The most common pattern was typical pemphigus foliaceus-like, with some lupus erythematosus-like features. A non-specific, chronic dermatitis pattern prevailed in the clinically controlled patients taking daily corticosteroids. In the patients who have had the most severe and relapsing pemphigus, early sclerodermatous changes and scleredermoid alterations prevailed in their reticular dermis. In addition to the scleredermoid alterations, the reticular dermis showed a paucity of appendageal structures. On the contrary, in the palms, a similar pattern was seen in all cases, including thickening of the stratum corneum, hypergranulosis, edema in the papillary and reticular dermis and a dermal perivascular lymphocytic infiltrate. The direct immunofluorescence of the glabrous vs. the non-glabrous skin also showed some differences. We conclude that the histopathologic features of this new variant of endemic pemphigus are complex, therefore, classical histopathologic features previously described for superficial, endemic pemphigus cannot be used alone to diagnose this disease.