Definition:

Pemphigus is an autoimmune blistering disease of the skin and mucous membranes characterized by circulating autoantibodies that target desmosomal components as well as other epithelial antigens and impair keratinocytes adhesion with subsequent acantholysis. Although the precise pathomechanisms of pemphigus have not yet been fully elucidated, recent studies have shown that desmosome disassembling involves not only the direct inhibition of desmosome formation caused by IgGs, but also desmosome remodeling. Pemphigus can be divided into non-inflammatory types, which are the major and common types, and inflammatory types, which are much less common and include necrolytic (apoptotic) type. Non-inflammatory pemphigus includes two types: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The former is caused by autoantibodies to desmoglein (Dsg) 3 only or to both Dsg1 and Dsg3 and generates clinically multiple flaccid blisters and erosions due to acantholysis at the lower, typically along the suprabasal, layers in the epidermis and mucous membranes. The latter is caused by autoantibodies to Dsg1 and clinically characterized by very fragile superficial blisters and large leafy scales due to acantholysis at the granular cell layer in the epidermis, but not observed in the mucous membranes. Inflammatory types of pemphigus include pemphigus herpetiformis (PH), pemphigus vegetans (PVeg) and the so-called paraneoplastic pemphigus (PP). Because pemphigus is an autoimmune disease, the most common treatment is the administration of oral steroids to inhibit antibody production, combined with the use of topical agents to prevent infection, protect the eroded areas and promote epithelialization. Other concomitant therapy can include the use of immunosuppressants, plasma exchange, and the administration of high-dose intravenous immunoglobulin (IVIG).