Nevus of Ota is a condition where hyperpigmentation occurs around the eye and sometimes in the eye itself. Hyperpigmentation is when some patches of skin are darker than the surrounding skin.
Nevus of Ota is also known as oculodermal melanocytosis.
It’s a type of dermal melanocytic hamartoma, which means there are an increased number of melanocytes, or melanin-producing cells, in the tissues.
Symptoms of Nevus of Ota
Nevus of Ota usually looks like a bluish or brownish pigment and appears in the areas of your face controlled by your trigeminal nerve. This nerve runs along the side of your face and is responsible for providing feeling to your face.
The areas that can be affected are your eye area, forehead, temple, cheek, and nose. About half of people with this condition have hyperpigmentation in their eyes as well.
Most often, the hyperpigmentation is unilateral, which means it occurs on only one side of your face. But 5 to 10% of those with nevus of Ota may have it on both sides of their face (bilateral).
The hyperpigmentation may darken and extend with age, such as during puberty and after menopause. Sunlight can also darken the lesions.
There is a similar skin condition called nevus of Ito. It has many of the same features to nevus of Ota but appears on the shoulder and side of the neck.
There are some other skin conditions that can involve hyperpigmentation and are often confused with nevus of Ota. These include:
- Congenital melanocytosis. Also known as Mongolian spots, this typically doesn’t appear on the face. The patches often resolve by themselves between the ages of 3 to 6 years.
- Melasma. This is usually linked to pregnancy and is sometimes called “pregnancy mask.” It typically occurs on both sides of the face and looks brownish instead of bluish.
- Blue nevus. This is a blue-colored mole that can appear anywhere on the skin and doesn’t change with age.
- Hori nevus. This hyperpigmentation resembles the nevus of Ota but usually appears on both sides of the face.
Causes of Nevus of Ota
Researchers have not come up with a definite cause of nevus of Ota. Some possible theories that have been suggested include hormonal reasons, radiation exposure, as well as genetic influences.
Who’s More Likely to Get Nevus of Ota?
Nevus of Ota is more common among people who are of Asian and African descent, and it’s more common in women than men.
The hyperpigmentation of the skin usually occurs at birth. But in some individuals, this can appear during puberty or pregnancy because of hormonal changes.
Complications of Nevus of Ota
People with nevus of Ota that extends to the eye have an increased risk of glaucoma.
Glaucoma is a group of eye diseases that damage your optic nerve. It can cause loss of vision and blindness. Many people with glaucoma don’t have any symptoms, and you may only notice the damage when you begin to lose your side (peripheral) vision. There’s no cure for glaucoma, but early treatment can help.
Nevus of Ota may also lead to malignant melanoma, a type of skin cancer, although this is rare. In one very rare case, the malignant melanoma was found as a tumor pushing against the eyeball.
Due to these complications, it is important to see your doctor yearly if you have nevus of Ota. If there are any changes to your lesions or if your vision changes, talk to your doctor.
Diagnosis of Nevus of Ota
There isn’t a diagnostic test to confirm if you have nevus of Ota. Instead, your doctor will be able to diagnose it by examining your skin. They will also take your medical history and conduct a physical exam.
Your healthcare professional may carry out some eye tests such as a slit lamp exam, a dilated eye exam, and a test to check the fluid pressure inside your eye. They may also look inside your mouth to check for any pigmentation.
You may have to undergo a skin biopsy if your doctor is concerned that there may be ulceration of your skin or there are papules (raised areas) of your skin. In a skin biopsy, a small sample of skin is cut and sent to a lab to be tested.
Treatment of Nevus of Ota
Nevus of Ota is typically benign, but some people may want to have it removed for cosmetic reasons.
There are a variety of treatments available. Experts note that some of these treatments may lead to scarring. These treatments include:
- Surgery to remove the lesions
- Chemical peels
- Topical hydroquinone-based bleaching agents
Pulsed Q-switched lasers have been found to be effective at treating nevus of Ota. These lasers target the melanocytes and destroy the pigmentation.
A study of people at a Korean hospital with nevus of Ota found that Q-switched lasers are a reliable and effective treatment, and they resulted in significant improvement in pigmentation. The pigment was removed, and there was a regeneration of collagen, the protein that holds your body together.
Another study found that adults who had successful Q-switched laser treatment usually experienced repigmentation within 2 to 3 years.
After these treatments, be careful to prevent hyperpigmentation from happening again. Avoid being directly in sunlight and wear broad-spectrum sunscreen.
If you think you may have nevus of Ota, contact your doctor to discuss what treatments are right for you.