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| Pemphigus Foliaceous |
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Definition: Pemphigus foliaceus (PF) is a blistering disease caused by antibodies directed against the glycoprotein desmoglein-1. It is milder than Pemphigus Vulgaris. Description: Blisters are located mainly on the chest, back, face and scalp, only rarely on mucosal surfaces. Actually, the absence of oral lesions distinguishes PF from PV. Diagnosis: Histopathology is the most reliable tool to diagnose PF. Dsg-1 antibodies can be detected in the serum by ELISA and can be demonstrated on skin sections by direct immunofluorescence. The fluorescent staining produces a fishnet-like pattern that is indistinguishable from that seen in pemphigus vulgaris. Types: These antibodies interfere with desmoglein-1 function and ultimately detachment of the keratinocytes (acantholysis) in the upper layer of the epidermis, with resulting blisters. Desmoglein-1 antibodies induce blisters when injected into the peritoneum of newborn mice, and can also transfer the disease from mother to fetus. The resulting neonatal pemphigus foliaceus, however, is extremely rare and even rarer than neonatal pemphigus vulgaris. The mouse model and the evidence of mother-to-fetus transmission provide direct evidence that PF is an autoimmune disease mediated by antibodies. T cells also participate in the pathogenesis of PF, and in fact the majority of patients have circulating T lymphocytes that specifically proliferate in response to desmoglein-1. PF can occur in a sporadic form or also in endemic form. The sporadic form affects adults and equally males and females. The endemic forms (named fogo selvagem, wild fire) occur in rural areas of south central Brazil, and also Columbia and Tunisia. Urbanization causes a dramatic decrease in disease incidence. Although microorganisms have long been suspected as initiators of the disease, no microbes have been cultured or identified in skin lesions. Fogo selvagem affects more children and young adults than the sporadic form, and it is slightly more prevalent in women (60% of the cases are females) (Ref 5). A review on fogo selvagem, containing also two photographs of a woman with this disease, can be seen by clicking here (Ref 6).
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Links to other Resources: www.pemphigus.org |
