Linear IgA bullous dermatosis mimicking oral lichen planus.

Linear IgA bullous dermatosis (LABD) is an autoimmune disease characterized by blisters on the skin and mucous membranes. Polycyclic, grouped bullae on cutaneous skin are the most characteristic clinical feature of LABD. Lesions are often indistinguishable from bullous pemphigoid or may resemble dermatitis herpetiformis. Oral lesions may be seen in 5% to 70% of patients with LABD, and in some cases, the oral mucosa may be the only area of involvement. Herein, we report a patient with LABD involving only the oral mucosa clinically. The entity histologically mimicked oral lichen planus, which challenges accurate diagnosis and emphasizes the importance of direct immunofluorescence.