Lichenoid epidermal nevus: "linear lichen planus".
A 3-year-old girl had an eruption that showed clinical and histologic evidence of both a verrucous epidermal nevus and a lichenoid tissue reaction. Linear plaques had been present on her right lower limb for 2 years. Microscopic features included hyperkeratosis, papillomatosis, acanthosis, a bandlike lymphohistiocytic infiltrate that obscured the dermoepidermal junction, Civatte bodies, and melanophages. Lichenoid epidermal nevus is a new variant of linear verrucous epidermal nevus. At least some of the cases previously diagnosed as linear lichen planus probably represent lichenoid epidermal nevus. There is a parallel between lichenoid epidermal nevus and the entity described as inflammatory linear verrucous epidermal nevus, which frequently was misinterpreted as linear psoriasis before it was recognized as a linear verrucous epidermal nevus with psoriasiform features.