LAUSR

A 13‐year‐old girl presented with a 7‐month history of recurrent oral ulcers and pain on swallowing. She first experienced peeling and soreness of the upper gingiva accompanied by a sore throat of several weeks’ duration before temporary and incomplete resolu‐ tion. Since then, she reported a recurrence of similar episodes lasting 2‐4 weeks with mild swelling of the lips and tongue. Her dermato‐ logic physical examination showed red erosions along the attached gingiva of the maxillary anterior teeth as well as round, well‐defined, 5‐8 mm ulcers on the bilateral tonsils (Figure 1). A punch biopsy of the gingiva was taken for histology (Figure 2) and direct immunoflu‐ orescence (Figure 3). What is the diagnosis?