Koebner phenomenon of the ear canal skin.

The Koebner phenomenon originally described the appearance of psoriatic lesions in the uninvolved skin of patients with psoriasis as a consequence of trauma. We describe a case of concurrent lichen planus and sarcoidosis in the auditory canal, which represents an unusual manifestation of the Koebner phenomenon. This is the first case of concurrent lichen planus and sarcoidosis in the head and neck region and highlights the need for biopsy to allow accurate histopathological diagnosis and treatment.