Adult Onset Nevus of Ota: Dermoscopic Characterization of a Rare Entity - A Case Report

Abstract

Introduction: Nevus of Ota (NOO) is a benign dermal melanocytic pigmentary disorder, which is characterized by abnormal blue hyperpigmentation of the skin of the face and oral cavity and it usually follows the distribution of the ophthalmic and maxillary division of the trigeminal nerve. It is comparatively rare in the Indian population. The onset of nevi can occur either at or soon after birth, but there are very few rare cases with it onset in the adulthood. We report the case of a 40-year-old female with the adult onset of NOO. Methods: A 40-year-old female born out of nonconsanguineous marriage presented with a chief complaint of hyperpigmentation over the right half of the face for 6 years. The family history was noncontributory. Cutaneous examination revealed a unilateral, diffuse, homogeneous, slate colored, macular pigmented lesion over the right upper, and middle one-third of the face with an irregular border. Ophthalmological examination revealed similar pigmentation in the right sclera. Results: Dermoscopic findings corroborated with the diagnosis of NOO. Conclusion: Very few cases of late onset (beyond 30 years) NOO have been reported in the literature. It is a rare entity in the Indian sub-continent, more so in adults. This case highlights the importance of keeping an eye out for such diagnoses even in patients with the late onset of the disease as the psychological impact of the disease is high and the lesion, although benign, can rarely transform into malignant melanoma.