Nevus of Ota
Definition: Nevus of Ota , or oculodermal melanocytosis, is a hamartomatous disorder of the melanocytes that predominantly involves the skin of the face and eyes, and mucous membranes. Characteristically, the lesions follow the distribution of the first and second branches of the trigeminal nerve.
Etiology: Developmental. Hyperpigmentation is due to melanin-producing melanocytes in the dermis that have failed to reach the epidermis or epithelium during fetal life.
Clinical features: The skin lesions present as multiple mottled black or brown macules varying in size from 1 mm to several millimeters (Fig. 91). The oral lesion presents as asymptomatic blue or blue-black dots or patches that usually involve the palate and buccal mucosa (Fig. 92). Hyperpigmentation of ipsilateral sclera is a common sign, while involvement of the cornea, iris, fundus, oculi, and retina is rare. Other sites such as nasal mucosa, pharynx, and tympanum may be less commonly affected. The disorder usually appears in early childhood before the age of 1 year and around puberty. About 70-80% of the cases are female. Malignant transformation of nevus of Ota is very rare. The diagnosis is mainly based on the history and the clinical features.
Laboratory tests: Histopathological examination.
Treatment:Laser and camouflage of face lesions.
