Extrusion of pilosebaceous units into blisters of patients affected by a new variant of endemic pemphigus in El Bagre, Colombia, South America

Background A new variant of endemic pemphigus foliaceus is present in El Bagre, Colombia, and surrounding municipalities (El Bagre-EPF) that affects the skin and in some presentations affects other organs with autoantibodies directed against cell junctions. Methods We studied 200 El Bagre-EPF patient perilesional skin biopsies, as well as 200 skin biopsies from normal controls in the endemic area. Results We observed blister extrusions of sebaceous glands or entire pilosebaceous units via the isthmus in 23% of the patients and not in the controls. Conclusions The extrusion of hair follicular unit contents is consistent with our previous pathologic findings of autoreactivity to these units, and their observed clinical decrease in patients affected by El Bagre-EPF.