Lichen planus‐like contact dermatitis due to methacrylic acid esters

Summary We report a patient who had lichen planus-like lesions on sites repeatedly exposed to methacrylic acid esters used in the car industry. Histologically, the lesions showed all the features of classical lichen planus. Patch testing revealed positive reactions to methacrylic acid esters in concentrations as low as 5 × 10−3%. As dental devices contain methacrylic acid esters, it is possible to speculate that methacrylic acid esters may be one of the causative agents for oral lichen planus.