What is nevus of Ota?
Nevus of Ota is a type of dermal melanocytosis (excessive melanocytes in the tissues) that causes the hyperpigmentation of an eye and the surrounding area. It often takes the form of bluish or brownish pigment around the eye, along with this pigment appearing on the whites of the eye.
Some individuals may also experience nevus of Ota on the forehead, nose, and cheeks. Others can experience it in the irises or whites of their eyes.
It’s estimated that about 50 percent of all cases of nevus of Ota are present at birth, while the rest typically develop during adolescence. Read on to find out more about this condition and what you can do.
What are the symptoms of nevus of Ota?
Nevus of Ota is typically unilateral, meaning that it usually involves only one side of the face. In some cases, it can present bilaterally on both sides of the face. If this occurs, the condition is referred to as nevus of Hori.
The hyperpigmentation of the skin around the eyes and on the face usually appears to be blue-grey or brown in hue. People with nevus of Ota may experience hyperpigmentation on any of the following areas of the face:
- area around the eye
- side of the face
- whites of the eyes
The hyperpigmentation caused by nevus of Ota appears in areas controlled by the trigeminal nerve. This nerve is located in the side of the face and is responsible for the sensation, or feeling of the face.
Nevus of Ota that affects the eyes themselves can cause thickening of the tissues in and around the eyes.
Although this form of dermal melanocytosis may appear to be light during childhood, it can darken and grow as the person matures. Its color might also vary slightly depending on factors like weather conditions, hormones, or illness.
Areas of hyperpigmentation may appear or grow gradually over a long period of time. However, the condition doesn’t spread beyond the areas of the face controlled by the trigeminal nerve. It’s also not contagious.
What causes nevus of Ota and who gets it?
Currently, there’s no definitive research that shows the root cause of nevus of Ota.
Some researchers believe that it could be caused by a genetic mutation. Others argue that hormonal factors or radiation may cause it, though more research is needed to confirm these things.
Nevus of Ota is much more commonly found in females than males, with an estimated 5:1 ratio. It also occurs more commonly in people of Asian or African descent. However, nevus of Ota can present in people of all different skin pigmentations.
Caucasian people are the least likely to develop nevus of Ota. Despite this, they’re the most likely to develop malignant melanoma in association with the condition.
How is nevus of Ota diagnosed?
If you’re experiencing hyperpigmentation of the skin near and around your eyes, it’s important to see a doctor for an appropriate diagnosis. Your dermatologist will observe the discoloration.
While the diagnosis of nevus of Ota is usually made on appearance alone, they also might take a small biopsy of the skin to confirm the presence of numerous heavily-pigmented melanocytes. This would allow them to diagnose dermal melanocytosis.
If the whites of your eyes are pigmented with blue-grey or slate brown, an eye doctor will examine your eyes with a biomicroscope. Your doctor may also dilate your eyes and examine them with an ophthalmoscope. In some cases, your ophthalmologist may opt for an ultrasound of your eyes to investigate further.
If you have hyperpigmentation on areas of your body besides those typically affected by nevus of Ota, your doctor may want to investigate further before giving you a definitive diagnosis.
Other diagnoses could include:
- nevus of Ito, hyperpigmentation of the arms, shoulders, underarms, and neck
- nevus of Hori, a condition almost identical to nevus of Ota which affects both sides of the face
- other forms of dermal melanocytosis that present in other locations
Your doctor will probably also want to investigate any unusual moles and birthmarks. Hyperpigmentation isn’t always caused by dermal melanocytosis. Some medications can cause abnormal pigmentation of the skin as an adverse side effect.
A person experiencing hyperpigmentation of the facial skin may learn that they have melasma. This can be caused by:
- UV radiation
- hormonal changes or therapies
- an under-functioning thyroid
- medications such as hormonal contraceptives, or birth control pills
Erythema can also cause benign, darkened skin patches on the upper body. In other cases, a person who has sustained burns or other trauma to the skin might experience hyperpigmentation of the tissues as they heal from injury and inflammation.
How is nevus of Ota treated?
Laser treatments are the most effective corrective approach to nevus of Ota, although they must be repeated more than once, with multiple approaches and applications. The laser treatments work to destroy the melanocytes that cause the bluish hyperpigmentation, with the goal of returning the skin to its natural pigment.
Laser therapy tends to be most effective in individuals with lighter skin tones. These procedures may cause scarring at the treatment site. It’s also not uncommon for the hyperpigmentation to return even after repeat laser treatments. In some cases, the nevus of Ota can return darker than its original hue.
People with nevus of Ota may opt to cover the hyperpigmentation with cosmetic products instead of laser surgery. These products might include camouflaging creams, foundation, or concealer. There are multiple techniques someone may use to conceal the lesions. These include contouring, concealing, and using color-correcting products.
Can nevus of Ota cause complications?
People with nevus of Ota extending to the eye are more likely to develop glaucoma. Doctors believe this is because the melanocytes that cause the hyperpigmentation block the flow of fluids in the eye, raising the pressure in the eye.
If nevus of Ota affects your eye, visit your eye doctor regularly for checkups.
There’s evidence that the condition may also lead to malignant melanoma, which can become deadly if not treated. Visit your doctor annually for skin cancer checks.
What’s the outlook for nevus of Ota?
Nevus of Ota can sometimes be treated, if desired. Without treatment, the lesions will typically remain unchanged throughout your life. The lesions may also darken as a result of sun exposure.
Aside from their physical appearance, nevus of Ota is benign. However, you should visit a dermatologist and an optometrist regularly to be screened for symptoms of glaucoma and malignant melanoma, as your risk for these may be higher.