Toluene induced exanthematous lichen planus: Report of two cases

Lichen Planus (LP) is a chronic mucocutaneous disease with several variants defined by the configuration of lesions, the morphological appearance, and the site of involvement. Although exact cause of LP is not known, it is thought that it is most likely an immunologically mediated reaction especially a cell-mediated immune response of unknown origin. Typical lesion is seen as a pruritic, papular eruption characterized by its violaceous color; polygonal shape; and, sometimes, fine scale. The size can vary from 1 mm to greater than 1 cm in diameter . It is most commonly found on the flexor surfaces of the upper extremities, on the genitalia, and on the mucous membranes. The clinical presentation of the disease has several forms: actinic, annular, atrophic, erosive, follicular, hypertrophic, linear, pigmented, vesicular/ bullous and eruptive/exanthematous. “Exanthematous” or “eruptive” LP is a rare variant of the disease. Herein we report a 15 year-old boy, and a 32-year old man with a 1.5 and 3-month history respectively, of acute, episodic and eruptive mucocutaneous LP after a toluene exposure. To the best of our knowledge, our patients are the first cases of exanthematous mucocutaneous lichen planus that were caused by toluene exposure.