Lichen planus and lichen sclerosus overlap.

Lichen planus and lichen sclerosus share several common features, including lymphocytic infiltration at the dermal-epidermal junction, clinical involvement of both skin and mucosa, erosive disease of mucosal surfaces, and the occasional occurrence of squamous cell carcinoma at the site of chronic, erosive mucosal lesions. In spite of these similarities, there are remarkably few reports of patients who concurrently have evidence of both diseases. We report a patient who had oral lesions of lichen planus and penile lesions of lichen sclerosus and we review possible mechanisms to explain this association.