Pemphigus vegetans of the folds (intertriginous areas).

Pemphigus vegetans (P Veg), the rarest form of pemphigus, is thought to be a variant of pemphigus vulgaris (PV). Classically, two subtypes of P Veg are recognized: (1) Neumann P Veg, which usually begins as PV with vesicles and bullae that rupture to form hypertrophic granulating erosions, then evolving into vegetating exuding masses; (2) Hallopeau P Veg, initially characterized by pustular lesions that, after rupturing, merge and gradually evolve into vegetating erosions with a centrifugal expansion. The disease typically affects the big folds (axillary, inframammary, inguinocrural, intergluteal), where semiocclusion, maceration, and mixed infections continuously incite exudation and granulation tissue formation (wet P Veg). In nonintertriginous locations, the vegetating buttons can dry out to change into warty, fissured, painful, seborrheic keratosis-like lesions (dry P Veg). Histologic examination indicates hyperplastic epidermis with intramalpighian leukocyte microabscesses and indistinct traits of suprabasal acantholysis. Immunofluorescence findings are similar to those of PV. Diagnosis is straightforward when PV lesions coexist. Difficulties can arise in cases with nonflexural location. Cytology (Tzanck test), histology, immunofluorescence, and ELISA search for anti-desmoglein antibodies are the diagnostic laboratory tools. Systemic treatment is similar to that for PV, high-dose steroids being the first choice therapy. Immunosuppressive agents and etretinate may allow a steroid-sparing effect. Topical treatment is aimed at countering the granulation tissue formation by means of several strategies (sublesional steroid injection, application of medicated gauzes in the involved flexures, chemical cautery or surgical excision of vegetating lesions).