Case 29a

by Professor Chua

This one year-old girl was referred by the paediatrician for ocular assessment because of discoloration of the left upper face (mainly in the temporal area and cheek) and left sclera. Further questioning revealed that the patient also had some pigmentation over the right shoulder as shown.

Figure 1. Pigmentation of the sclera and the left upper face.

Figure 2. Pigmentation of the sclera.

Figure 3. Bluish black pigmentation of the right shoulder area.

a. What is the diagnosis?

This baby has two conditions. The pigmentation of the sclera and face is called naevus of Ota and that of the should is naevus of Ito. They may represent incomplete migration of melanocytes from the neural crest to the epidermis during the embryonic stage.

 

Naevus of Ito, also called naevus fusculocoeruleus ophthalmomaxillaris, was first described in 1939 by the Japanese dermatologist M. T. Ota. The pigmentation usually involves skin innervated by the first or second branch of the trigeminal nerve. The pigmentation is made up of dermal melanocytes and usually appears early in infancy. Associated lesions include melanocytosis of the sclera, the tympanic membrane, oral and intranasal mucosa and leptomeninges. Nevus of Ito was described by Minor Ito in 1954. It is a dermal melanocytic condition affecting the shoulder area. Nevus of Ito can occur in association with nevus of Ota as in our patient.

Nevi of Ota and Ito occur most frequently in Far Eastern Asian populations, with an estimated prevalence of 0.2-0.6% for nevus of Ota in Japanese persons. The condition is less common in other racial groups. Nevus of Ito is less common than nevus of Ota, although the true incidence is unknown. The male-to-female ratio is 1:5 for nevus of Ota. The ratio for nevus of Ito is unknown.

 

Cosmetic camouflage is the best management for naevus of Ota by masking the disfiguring markings. The pigmentation can also be treated with laser which works by destroying the dermal melanocytes. However, recurrence is common after treatment and occasionally with even darker pigmentation.

 

b. What are the potential ocular complications?

Ocular complications are rare and there are two main ones:

a. Open-angle glaucoma.

b. Malignant melanoma. This appears to be more common amongst Caucasians with nevus of Ota.

References:

1. Hidano A, Kajima H, Ikeda S, et al: Natural history of nevus of Ota. Arch Dermatol 1967 Feb; 95(2): 187-95.

2. Ito M: Studies on melanin XXII. Nevus fuscocaeruleus acromio-deltoideus. Tohoko J Exper Med 1954; 60: 10.

3. Ferguson RE Jr, Vasconez HC. Laser treatment of congenital nevi. J Craniofac Surg. 2005 Sep;16(5):908-14. Review.