P08 Linear IgA Bullous Dermatosis: Treatment Challenge

Linear IgA bullous dermatosis (LABD) is a rare idiopathic or drug-induced autoimmune blistering disease characterized by widespread annular blisters caused by IgA autoantibodies directed against different antigens of the basement membrane zone (BMZ) of the skin and mucosae. Linear deposits of IgA at the dermoepidermal junction are a dominant diagnostic feature. Dapsone is the most commonly used systemic treatment with complete remission achieved in most patients. A 15-month-old boy presented with widespread annular blisters, erosions and haemorrhagic crusts on the face, scalp, torso, extremities and genital skin. An episode of acute bronchitis preceded the skin lesions. The patient was otherwise healthy. A skin biopsy of a lesion showed subepidermal blistering with neutrophils and eosinophils in the superficial dermis. Direct immunofluorescence revealed linear IgA and discrete linear IgG deposits along the BMZ. Treatment with oral prednisone 1–2 mg kg–1 daily and dapsone 1–2 mg kg–1 daily resulted in modest control of LABD and prompted introducing concomitant medications in the following sequence, IVIG, methotrexate 10 mg weekly for 6 months, and ciclosporin 5 mg kg–1 daily over 4 months, all with moderate disease control. Prednisone was stopped after 2 years and the LABD cleared with dapsone 2 mg kg–1 daily. The attempt of tapering the dapsone resulted in a flare. The treatment of LABD is based on case reports and varies with the degree of involvement and identification of inciting factors. The severe, treatment-resistant LABD in our patient, managed by the multidisciplinary team and shared care with the parents, resulted in a good and safe treatment outcome.