Linear IgA bullous disease (LABD) is a rare autoimmune blistering disease characterized by subepithelial bullae and linear IgA deposition along the basement membrane zone of the epidermis. Lesions present as pruritic papulovesicles and tense bullae which may coalesce forming annular or polycyclic urticarial plaques with blistering on the edge of the lesions forming the classic “string of pearls” sign. Lesions may affect the face, trunk, and extensor extremities. Incidence rates range from 0.5 to 2.3 cases per million individuals per year. Due to its rare occurrence, there are only a few documented reports on cases of LABD, particularly in the Filipino population.
A 33 year-old Filipino female consulted because of a 3-week history of severely pruritic vesicles and crusts on the face, trunk, and arms. Patient noted no gastrointestinal symptoms on consultation. Skin punch biopsy revealed subepidermal blisters with collection of neutrophils at the dermal papillae. Direct immunofluorescence showed strong (+2) deposits of linear IgA at the dermo-epidermal junction in perilesional skin thus validating the diagnosis. The patient’s serum was negative for IgA anti-tissue transglutaminase and IgA antiendomysial antibodies. Patient was treated with topical corticosteroids and Dapsone 50 mgs OD with remarkable improvement.
Linear IgA bullous disease has very few reported cases especially in the Philippine setting. Dapsone is considered the first-line treatment. The disease may persist for a decade or longer, and relapses may occur. Careful history-taking accompanied by the histological, immunofluorescence, and serological findings must be done to ensure proper treatment and good prognosis.