Linear psoriasis.

A 33-year-old man presented with verrucous, red-brown papules, which coalesced into linear plaques on the right buttock, waist, thigh, and genitals. A skin biopsy was consistent with psoriasis, and the unilateral distribution in a linear pattern led to a diagnosis of linear psoriasis, which is a rare variant of psoriasis. Although histopathologically it can be difficult to distinguish from inflammatory linear verrucous epidermal nevus (ILVEN), linear psoriasis presents in adulthood and responds to conventional topical antipsoriatic therapies.