Inflammatory linear verrucous epidermal nevus associated with erosive monoarthritis

Inflammatory linear verrucous epidermal nevus and linear psoriasis are different entities with clinical and histopathologic similarities. Isolated reports of inflammatory linear verrucous epidermal nevus with concomitant psoriasis or a positive family history of psoriasis have been described, and the possibility that inflammatory linear verrucous epidermal nevus may be a mosaic form of cutaneous psoriasis has been postulated. We report a 17‐year‐old boy with a congenital, linear, erythematous, keratotic plaque on the dorsum of the fifth finger of the left hand with ipsilateral nail dystrophy. Histopathologic examination showed epidermal hyperplasia with alternating orthokeratosis and parakeratosis. During follow‐up, he developed erosive monoarthritis of the distal interphalangeal joint. This case seems to confirm the association between inflammatory linear verrucous epidermal nevus and arthritis and supports a possible relationship between inflammatory linear verrucous epidermal nevus and psoriasis.