A Case of Longitudinal Melanonychia Secondary to Hydroxyurea

Melanonychia commonly appears as a longitudinal band, starting from the matrix and extending to the tip of the nail plate. Less often it presents a transverse band or may inolve whole nail plate. Cutaneous side effects of hydroxyurea are described in 13% of patients including increased pigmentation, hyperkeratosis, skin atrophy, xerosis, lichenoid eruptions, palmar and plantar keratoderma, cutaneous vasculitis, alopecia, melanonychia. Rarely, mucosal changes such as oral ulcers, stomatitis, hyperpigmentation of the oropharyngeal mucosa have been reported. Herein, a patient is reported who developed longitudinal melanonychia and periungual hyperpigmentation on his fingerand toenails several months after initiation of hydroxyurea therapy.