Hyperpigmentation around a teen’s eye

THE CASE

An adolescent girl is referred by her pediatrician to dermatology for evaluation of a birthmark on her face. 

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DERMCASE diagnosis: Nevus of Ota

Nevus of Ota (also known as "congenital melanosis bulbi," "nevus fuscoceruleus ophthalmomaxillaris," or "oculodermal melanocytosis") is a variant of Mongolian spot that presents with bluish-green to grey-brown pigmentation on the face. Approximately half of the cases are congenital, and the others typically are acquired in the teenaged years.    

Nevus of Ota occurs most frequently in Asians, with an estimated prevalence of 0.014% to 0.034%, and it is uncommon among Caucasians.¹ It also develops frequently in East Indians and African Americans, and is 5 times more common in females than males.²

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Nevus of Ota is caused by the entrapment of melanocytes in the upper third of the dermis, involving the first and/or second (ophthalmic and maxillary) branches of the trigeminal nerve. Although unconfirmed, investigators suggest that nevus of Ota may occur when melanocytes arising from the neural crest do not migrate to their normal position in the basal cell layer of the epidermis during early embryologic development.³ Whereas biopsy usually is not necessary to establish the diagnosis, histology shows uniformly distributed melanocytes in the dermis. Differential diagnoses include blue nevi, café au lait spots, melasma, and cutaneous melanoma.

Nevus of Ota is usually unilateral (90%), generally involving only 1 side of the face over the cheek, nose, forehead, temple, and around the eye; however, it also can be bilateral, although rarely.⁴ There have been a few case reports of oral mucosal involvement, which is extremely rare.² Given the involvement of the trigeminal nerve, it can cause discoloration of the eyelid, sclera, cornea, and/ or retina. The sclera is involved in two-thirds of patients, and scleral involvement is associated with an increased risk for glaucoma, which occurs in 10% of patients.⁵ For this reason, all patients with a nevus of Ota that involves any structure of the eye or eyelid should be referred to ophthalmology for routine screening.

Risk of melanoma

The lesion remains unchanged throughout life but it may darken with sun exposure. Because of its location and high visibility, nevus of Ota may be associated with major psychosocial issues for both children and adults. As a consequence, all patients should be evaluated for possible treatment with the Q-switched lasers that offer a good clinical response with little or no risk of scarring.¹

Essentially, nevus of Ota is similar in pathophysiology and appearance to the Mongolian spot, but differs in location. It is a benign condition that may be managed by the primary care physician. However, monitoring should continue given its rare potential to transform into a malignant melanoma.

REFERENCES

1. Chan HH, Kono T. Nevus of Ota: clinical aspects and management. Skinmed. 2003;2(2):89-96.

2. Shetty SR, Subhas BG, Rao KA, Castellino R. Nevus of ota with buccal mucosal pigmentation: a rare case. Dent Res J (Isfahan). 2011;8(1):52-55.

3. Hori Y, Takayama O. Circumscribed dermal melanoses. Classification and histologic features. Dermatol Clin. 1988;6(2):315-326.

4. Magarasevic L, Abazi Z. Unilateral open-angle glaucoma associated with the ipsilateral nevus of Ota. Case Rep Ophthalmol Med. 2013; 2013: 924937.

5. Khawly JA, Imami N, Shields MB. Glaucoma associated with the nevus of Ota. Arch Ophthalmol. 1995;113(9):1208-1209.

Dr Gangaram is a third-year pediatric resident, Herman and Walter Samuelson Children’s Hospital at Sinai, Baltimore, Maryland. Dr Cohen, section editor for Dermcase, is professor of pediatrics and dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The author and section editor have nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article. Vignettes are based on real cases that have been modified to allow the author and section editor to focus on key teaching points. Images also may be edited or substituted for teaching purposes.