dermatologic disorders
Pemphigus Foliaceus
Introduction
Pemphigus foliaceus is an autoimmune blistering disorder in which lack of adhesion in the superficial epidermis result in cutaneous erosions. Diagnosis is by skin biopsy and direct immunofluorescence. Treatment depends on disease severity and includes topical or systemic corticosteroids. Other immunosuppressive therapies may be needed. Bullae are elevated, fluid-filled blisters ≥ 10 mm in diameter. Pemphigus foliaceus usually occurs in middle-aged patients, affecting men and women in equal numbers. An endemic form of pemphigus foliaceus, fogo selvagem, occurs in younger adults and children, particularly in South America. Pemphigus foliaceus may occur after use ofpenicillamine,nifedipine, orcaptopril. Pemphigus erythematosus, a form of pemphigus foliaceus localized to the cheeks, has immunologic features of pemphigus and Systemic Lupus Erythematosus (SLE) (IgG and C3 deposition on keratinocyte surfaces and basement membrane zone with circulating antinuclear antibodies); however, patients rarely are diagnosed with both diseases concurrently. Pemphigus foliaceus is mediated by IgG autoantibody against desmoglein 1 (Dsg1), a transmembrane glycoprotein cadherin important to cell–cell adhesion and signaling between keratinocytes ( General reference ; see figure Pemphigus foliaceus blisters form in the superficial layers of the epidermis. Pemphigus vulgaris blisters can form at any epidermal level but typically form in the lower aspects of the epidermis. Bullous pemphigoid blisters form subepidermally (lamina lucida of the basement membrane zone). In this figure, the basement membrane zone is disproportionately enlarged to display its layers. 