A case of oral mucosal fixed eruption caused by methacrylate

A 45-year-old otherwise healthy Japanese woman had suffered from multiple ulcers on her oral mucosa and blistering erythema on her hands for 2 years. She denied taking any medicines or dietary supplements. Oral mucosal and cutaneous examination showed sharply defined ulcers and erosions of her oral mucosa, and multiple sharply defined round bullous erythemas on her hands (Fig. 1a,b). The results of laboratory examinations were normal. In the serological tests, antibody titres for herpes simplex virus (HSV)-1 and HSV-2 were not elevated in her clinical course. Also, anti-desmoglein 1 and anti-desmoglein 3 antibodies were not detected. Biopsies were obtained from the buccal mucosal lesion (Fig. 2a) and the erythema on the back of her finger (Fig. 2b). Histological examination showed apoptotic keratinocytes in the epidermis, and infiltrating lymphocytes in the epidermis and dermis. Immunofluorescence analysis showed no deposition of IgM, IgG, IgA, or serum complement (C3). During follow-up, the patient’s symptoms were exacerbated after treatment of cavities. Two days after treatment, a blister appeared on her right lower buccal