Naevi of Ota and Ito

What are naevi of Ota and Ito?

Nevi of Ota and Ito are coloured skin markings of slate-brown or blue/grey colouring. They are unusual birthmarks in which the melanocytes (pigment cells) are found deeper than normal (in the dermis instead of the epidermis).

The difference between a naevus of Ota and a naevus of Ito is its location. Naevus of Ota is on the forehead and face around the eye area; naevus of Ito is on the shoulder and upper arm area.

Naevus of Hori has a similar appearance to the naevus of Ota. However, it is not present at birth, and it often affects both sides of the face.

Naevus of Ota

Naevus of Ito

How do you get these naevi, and who is at risk?

It is not known why these naevi occur.

Naevi of Ota are much more common than naevi of Ito and are present at birth in 50% of cases. Naevi of Ota may also suddenly appear during adolescence. Thus researchers suggest hormones play a part in their development.

Naevi of Ota and Ito are most commonly found in Asian populations; 0.2-0.6% of Japanese people have nevi of Ota. They appear more frequently in females. Both forms of naevi are very uncommon in Caucasians.

What are the signs, symptoms and complications?

Naevus of Ota

• Hyperpigmentation usually located on one side of the face (unilateral) but can be on both sides (bilateral)
• May involve hyperpigmentation of parts of the eye: sclera, cornea, iris, retina
• May involve hyperpigmentation of the inside of the mouth
• Naevi may slowly grow and darken until adulthood is reached
• Colour or perceived colour of naevi may change according to personal and environmental conditions, e.g. fatigue, menstruation, hot weather
• May rarely cause glaucoma
• Malignant melanoma very rarely develops, particularly in Caucasian cases

Naevus of Ito

• Hyperpigmentation located over the shoulder girdle region, usually on one side only
• Possible sensory changes to the involved skin

What treatments are available?

Treatment of a naevus of Ota is usually cosmetic camouflage to cover the disfiguring markings. Laser treatment and intense pulsed light (IPL) work by destroying the dermal melanocytes. Unfortunately recurrence is common after laser clearance, sometimes resulting in a darker hue.

If the eye is affected, arrange for regular eye examinations to detect glaucoma. You should see a dermatologist if there is any change in the naevus, especially if you are fair-skinned.