ICD-11

Pemphigus is a group of chronic autoimmune skin diseases characterised by blister formation on the skin and the mucous membranes. The exact causes of the disease are unknown but the disease is mediated by auto-antibodies to desmosome components. Three clinical forms have been characterised. Pemphigus vulgaris, pemphigus foliaceus and pemphigus vegetans. Other variants exist, namely intercellular IgA dermatosis and paraneoplastic pemphigus.

Pemphigus foliaceus is a chronic autoimmune skin disease characterised by superficial blister formation on the skin mediated by auto-antibodies to the desmosome component desmoglein 1.

Pemphigus foliaceus is the less common form of pemphigus (10-20%) prevalence. Onset occurs in middle age but childhood cases occur. The disease presents with superficial blistering often manifest as scaly erosions particularly on the trunk, scalp and face. Mucosal lesions do not occur. Pemphigus erythematosus and pemphigus herpetiformis are variants. An endemic form exists in Brazil and adjacent areas, known as fogo selvagem. Autoantibodies directed against the desmosome component desmoglein 1 (a keratinocyte membrane molecule) cause intraepidermal clefting. Diagnosis is confirmed by standard histopathology showing intraepidermal blisters in the granular layer or just below the stratum corneum and direct and indirect immunofluorescence showing IgG at the cell surface of epithelial cells. The disease activity is roughly correlated with the level of circulating antibodies. Systemic steroids are the initial treatment of choice and can be combined with immunosuppressant drugs. The prognosis of pemphigus has markedly improved over the last decades nevertheless mortality does occur mostly as a consequence of infection.