Pemphigus Vulgaris is a fatal, or chronic autoimmune disorder affecting the skin. It is characterized by blistering of the epidermal and mucous membranes of the skin and acantholyis (separation of the epidermal cells). The blisters usually appear first in the mouth, before they are noticed all over the body. Invariably, the blisters rupture, causing pain. In fact, the lesions make the skin so tender, that even touching the skin can cause it to tear, a phenomenon called the Nikolsky effect.
PV is a rare disorder, affecting 0.5 to 3.2 cases per 100,000 people worldwide. It is seen to be more prevalent in Ashkenazi Jews and people of Mediterranean origin. Clinical diagnosis involves a visual examination of the skin lesions, followed by a skin biopsy to detect acantholysis. Direct and indirect immunofluorescence to detect desmoglein antibodies is also used for diagnosis. As of now, no cure is available for PV. Treatment involves administration of steroids, usually prednisone, and corticosteroids. Severe cases are treated similarly as burns. If left untreated, PV may lead to skin loss, oropharyngeal ulcerations, debilitation, sepsis and eventual death. Treatment is life-long, and may impart severe or disabling side effects.
The aetiology of PV is not clearly understood. However, it has been shown to be transmitted in families in an autosomal dominant fashion. The underlying cause of the disease is the production of antibodies against desmogleins, a group of cell surface molecules on keratinocytes. Desmosomes carry out an integral function in cell-cell adhesion. The attachement of the auto-antibodies to the desmogleins, inactivates the desmosomes, leading to a loss of cell adhesion. The exact cause of this autoimmune reaction or the genetic basis of the production of the anti-desmoglein antibodies is not known. However, occurrence of PV has shown association with the HLA serotypes DR4 and DRw6.