Pemphigus and pemphigoid.

Both pemphigus vulgaris and bullous pemphigoid are chronic, blistering, cutaneous diseases. Pemphigus vulgaris is characterized by fragile, flaccid bullae and erosions on the mucous membranes and skin. Corticosteroid therapy is necessary to prevent the high mortality. In bullous pemphigoid, tense bullae develop on the skin but not on the mucous membranes. The disease usually follows a benign course. In both disorders, the diagnosis is established by skin biopsies and direct and indirect immunofluorescence.