Bilateral nevus of Ota: a rare manifestation congenital type in a boy.

Background: The nevus of Ota is usually characterized by small, flat, unilateral, blue-black or gray-brown spots occurring on skin innervated by the first or second branch of the trigeminal nerve. It comprises dermal melanocytes, presumably arising due to the dermal arrest of cells migrating from the neural crest. Nevus of Ota is 3-5 times more common in women than men, and is classified into congenital type, appearing soon after birth, and acquired type, appearing during or after puberty.

Methods: We report on a six-year-old Japanese boy with the bilateral nevus of Ota. He was referred to our hospital because of bilateral hyperpigmentation of the face, present since birth. Our treatment consisted of Q-switched ruby laser irradiation under general anesthesia. The Q-switched ruby laser (Model IB101; Niic Co. Ltd., Tokyo, Japan), had a wavelength of 694.3 nm, a spot size of 5 mm, a 1 Hz repetition rate, a pulse duration of 20 nsec and fluence ranged from 3.0 J/cm2 to 6.0 J/cm2.

Results: Q-switched ruby laser irradiation improved his pigmentation, and will therefore be repeated several times.

Conclusions: This case of congenital bilateral nevus of Ota in a young male patient was very rare. And Q-switched ruby laser irradiation was effective as same as another nevus of Ota.