The mean age of onset of pemphigus herpetiformis (PH) is 65 years of age. Males and females are affected equally.
Clinically, PH resembles dermatitis herpetiformis with red, vesicular, bullous, or papular lesions, often in a herpetiform pattern. Severe pruritus is characteristic. Oral mucous membranes may be involved.
Light microscopic findings may be similar to pemphigus vulgaris with eosinophilic spongiosis and acantholysis. However, findings on histologic exam vary greatly and may not be helpful at the outset. Direct and indirect immunofluorescence demonstrate intercellular IgG primarily in the upper epidermis targeting desmoglein 1. Rarely, desmoglein 3 may be the target antigen.
PH typically follows a benign course. Patients respond well to treatment with a tendency to develop complete remission. However, the disease course in some patients may evolve into a picture resembling pemphigus vulgaris or pemphigus foliaceus.