Linear immunoglobulin A (IgA) disease is an uncommon bullous disease distinguished from bullous pemphigoid and dermatitis herpetiformis by linear deposits of IgA in the basement membrane zone.
Linear IgA disease has two main clinical variants—bullous disease of childhood and adult linear IgA disease. Although they vary clinically in minor ways, their immunofluorescence patterns are identical. The IgA autoantibodies target several antigens within the dermal-epidermal junction.
Infections and penicillins trigger more than one fourth of childhood and adult cases. Vancomycin, diclofenac, and NSAIDs also have been suggested as causes. Risk of linear IgA disease is increased in patients who have inflammatory bowel disease (possibly with a related pathophysiology that involves a generation of autoantibodies) or lymphoproliferative cancers (in adults) but not other autoimmune disorders.
In linear IgA disease, vesicular or bullous skin lesions occur frequently in a clustered (herpetiform) arrangement. In younger children, the face and perineum are often involved, and spread to the limbs, trunk, hands, feet, and scalp is common. In adults, the trunk is almost always involved, and the scalp, face, and limbs are often involved. Lesions are often pruritic and may burn. Mucosal involvement is common in both age groups; milia are not characteristic.
Diagnosis is by skin biopsy and direct immunofluorescence. The histologic features are not specific, but direct immunofluorescence shows IgA deposited along the basement membrane zone in a linear fashion.
Mild disease can be treated with topical corticosteroids. Erythromycin can be used in children. Dapsone and sulfonamides (using doses and precautions similar to those for dermatitis herpetiformis—see Treatment) and colchicine are alternatives. Often the cutaneous lesions respond before the mucosal lesions. Spontaneous remission occurs in most patients after 3 to 6 yr.
Last full review/revision June 2013 by Daniel M. Peraza, MD
Content last modified November 2013