Chapter 26: Nevus of Ota

INTRODUCTION

Nevus of Ota, also known as nevus fuscoceruleus ophthalmomaxillaris, represents a benign partially confluent macular brown-blue pigmentation of the skin and mucous membranes in the distribution of the first and second branches of the trigeminal nerve. It may be unilateral or bilateral. The ipsilateral sclera is frequently involved.

EPIDEMIOLOGY

Incidence: 0.4% to 0.8% of Japanese dermatology patients

Age: bimodal distribution at birth and puberty

Race: more common in Asians and blacks than whites

Sex: more females than males seek treatment for this condition; unknown if there is a sex predilection

Precipitating factors: sporadic, not an inherited disorder

PATHOGENESIS

Hyperpigmentation arises as a result of dermal melanocytes that have not migrated to the epidermis.

PATHOLOGY

Heavily pigmented, elongated, dendritic melanocytes are located among the reticular dermal collagen. Most typically, these melanocytes are found in the upper one-third of the reticular dermis but are also seen in the papillary dermis in some lesions.

PHYSICAL LESIONS

It presents as confluent or partially confluent brown-blue patches in the distribution of the first and second branches of the trigeminal nerve. Gray, black, and purple coloration may be present in some lesions as well. It can be unilateral or bilateral. The magnitude of involvement can vary from local periocular involvement to much of the side of the face. Approximately two-thirds of patients feature ipsilateral scleral involvement.

DIFFERENTIAL DIAGNOSIS

Melasma, café au lait macule, Hori’s macule blue nevus, bruising, ochronosis, argyria, photodermatoses, fixed drug eruption, and other medication-related eruptions should be considered in the proper clinical setting.

LABORATORY EXAMINATION

Biopsy may be indicated if the diagnosis is in question or to exclude the rare case of melanoma arising in this lesion.

COURSE

There is a bimodal distribution for nevus of Ota, birth and puberty. It remains relatively similar in appearance after initial presentation.

KEY CONSULTATIVE QUESTIONS

• Onset of eruption

• Medication history

MANAGEMENT

There is no medical indication to treat nevus of Ota. Cosmetic appearance, however, is distressing to patients. While cryotherapy and topical bleaching treatments have been utilized, the treatment of choice is Q-switched laser treatment.

TOPICAL TREATMENT

Makeup can camouflage or assist in camouflaging nevus of Ota. Topical medications are less effective than laser.