pemphigoid

Pemphigoid refers to a group of autoimmune blistering diseases characterized by an autoimmune attack at the basement membrane, producing subepidermal blisters. The best known forms are bullous pemphigoid and mucous membrane pemphigoid, also called cicatricial pemphigoid. Onset is usually in adults, especially the elderly.

Most cases involve IgG autoantibodies against hemidesmosomal proteins BP180 (BPAG2) and BP230 (BPAG1) at the dermal–epidermal junction. Complement activation and eosinophil recruitment lead to dermal-epidermal separation and tense blisters. Mucous membrane involvement is common in MMP and can cause scarring.

Clinical features include tense blisters on non-inflamed skin with itch in bullous pemphigoid; mucous membrane disease may affect the mouth, eyes, or other mucosa and can scar, particularly in ocular disease.

Diagnosis relies on biopsy showing a subepidermal blister with eosinophils, and direct immunofluorescence revealing linear IgG and/or C3 along the basement membrane. Serology for BP180 and BP230 antibodies supports the diagnosis.

Treatment depends on extent. Localized disease uses potent topical steroids; extensive disease requires systemic therapy with corticosteroids plus steroid-sparing agents such as azathioprine, mycophenolate mofetil, or methotrexate. Doxycycline with nicotinamide or rituximab are alternatives in selected cases.

Prognosis varies. Bullous pemphigoid usually responds to treatment, while MMP can cause permanent scarring, especially in the eyes. The condition is uncommon and management often involves dermatology, with eye care for MMP.