Nevus of Ota is a pigmented birthmark characterized by cyanotic nevus in the periocular region, which is common in Eastern peoples (although sometimes not always present at birth). In China, nevus of Ota accounts for about 0.4% of dermatology and 2.6% of plastic surgery outpatient visits, with a male to female ratio of 1:3. About half of the patients are discovered at birth, but some start to discover the disease in childhood, and some patients only gradually show it in adolescence, manifesting as patches of brown, gray and blue spots with unclear borders. The color of the lesions can be monochromatic or both of the above mentioned colors, and the color shades vary. Due to the different density and location of melanocyte distribution in the dermis, the patches can be light brown to dark blue, and different parts of the same lesion can have different colors. In some patients, the lesions have the tendency to increase slowly. The patches occur in the forehead, around the eyes, cheeks and zygomatic area, i.e., the area equivalent to the distribution area of area I and II of the trigeminal nerve, and may occupy all or part of the area. Some patients start to have long-term stability in childhood, and most experts believe that it will be more stable after puberty, but some people still have the tendency to grow slowly until they are about 30 years old. Nevus of Ota has no hereditary tendency, and there is no clear relationship with malignant transformation.
I. Classification of nevus of Ota.
1. Light.
(1) Light orbital type: pale brown spots, limited to the upper and lower eyelids.
(2) Light zygomatic type: light brown spots, limited to the zygomatic bone.
2.Medium Dark blue to purple-brown, distributed on eyelids, cheekbones and nasal roots.
3.heavy dark blue to brown, distributed in the area of the first and second branches of the trigeminal nerve innervation.
4.Bilateral type About 5%.
In addition, Tanino of Japan also proposed the following classification.
1, light type (also divided into eye socket type, zygomatic type, forehead type, and nasal flank type).
2. medium type.
3.Heavy type.
Bilateral distribution is divided into: symmetrical type (also divided into central type and marginal type), and asymmetrical type.
According to the color is divided into: brown type, cyan type.
According to the histological characteristics: superficial type (pigment cells are located in the superficial dermis, mostly brown in color), deep type (pigment cells are located in the deep dermis, mostly cyanotic), diffuse type (pigment cells are located in the whole dermis, mostly purple-blue).
According to the age, there are early onset (within a few years after birth) and late onset (after puberty).
There are also reports of glaucoma due to blocked pigmentation in the anterior chamber angle, combined with neurodeafness, ocular regression syndrome, ipsilateral congenital cataract and upper limb atrophy. Nevus of Ota does not fade throughout life and has no self-conscious symptoms. The chance of malignant transformation is extremely rare. The combination of malignant melanoma of the iris and choroid and malignant blue nevus has been reported in the literature.
Ito nevus belongs to the category of nevus of Ota, and the clinical manifestations and pathological changes of the two are identical except for the different distribution sites, which are mainly distributed in the area innervated by the posterior supraclavicular and lateral brachial nerves such as shoulder, cervical side and supraclavicular area on one side.
Clinical manifestations of nevus of Ota
Nevus of Ota and nevus of Ito are more likely to occur in people of color, such as oriental people and black people. They are more common in women. The lesions are light blue, gray-blue, brown-blue to blue-black or tawny patches or spots, with the central part of the patch being dark and the edges becoming lighter. Occasionally, some areas of the pigmented spots may be elevated or even have small nodules of corn to green bean size. The spots are distributed in clusters, with varying density, or with patches in the center and spots on the edges. The color of the lesions is aggravated by sun exposure, exertion, menstruation, and pregnancy. In some cases, the lesions become darker and larger during puberty. The most common sites of involvement are the periorbital, temporal, forehead, zygomatic, and nasal flanks, i.e., areas corresponding to the distribution of the second and second branches of the trigeminal nerve; the distribution is unilateral, occasionally bilateral (about 10%), and about 2/3 of patients have ipsilateral scleral blue staining. Extensive lesions may also involve the scalp, ears and neck, trunk, and upper and lower extremities. The mucous membrane of the oral cavity and nasopharynx can also be involved.
Ito nevus belongs to the category of nevus of Ota, and the clinical manifestations and pathological changes of the two are identical, except for the difference in distribution sites. Some cases can be accompanied by ipsilateral or bilateral nevus of Ota.
3.Laser treatment for nevus of Ota
Since there is a great difference between the lesion tissue of nevus of Ota and normal tissue, and different lesion tissues have different nature and different depths, so their absorption of laser wavelengths are different, so different wavelengths of cosmetic laser have their own indications for eye and periocular skin.
1.532nm laser wavelength: It is suitable for the removal of superficial pigmented nevus of the skin around the eyes. Such as birthmarks, nevus of Ota, nevus, coffee nevus, freckles, various pigmentation, eyebrow tattoo, eyeliner tattoo, as well as various hemorrhagic nevi, vascular lesions, etc..
2.585nm laser wavelength: It is suitable for various hemoglobin nevi and vascular lesions. 585nm is the strongest absorption peak of hemoglobin cells, which is the best wavelength for treating various hemoglobin nevi and vascular lesions, such as spider capillary dilation, hemangioma, rosacea, deep red spots, etc.
3, 650nm laser wavelength: adapted to the removal of tattoos and pigmented moles. Wavelength 650nm is the absorption peak of the green dye, it is the most effective for the removal of green pigment in professional tattoos, can also be used to remove general pigmentation moles;.
4, 694nm laser wavelength (ruby laser): adapted to the removal of nevus of Ota, heliochromia, freckles, and blue-black, black, green, coffee-colored tattoos.
5, 1064nm laser wavelength: adapted to deep pigmented lesions and dark-colored tattoos. 1064nm penetration of skin tissue is strong, can reach the melanocytes in the deeper layers of the skin or black-blue tattoo dye particles.
Four, nevus of Ota treatment
The use of laser for nevus of Ota treatment, if you want to achieve the desired effect, generally need 3-8 times of treatment, each treatment interval of more than 6 weeks, each treatment can be completed within a few minutes to tens of minutes, the patient feels the skin by the pulse beam of the beat, the postoperative pain mostly disappears quickly. The number of treatments is most closely related to the characteristics of the lesion, and secondarily to the laser wavelength mentioned above. From the pattern of melanin particles in melanocytes observed by the naked eye and the microscopic distribution of melanocytes, when the cells are distributed in the superficial dermis, they tend to be light brown or brown, and when they are distributed in the deeper dermis, they appear blue or gray-black, and the shade of the same color is related to the density of the distribution of melanocytes, and this pattern is very practical in judging the prognosis and the number of treatments when performing the treatment. It is suitable for all types of nevus of Ota, except for the sclera and conjunctiva of the eye.
The younger the child, the thinner the skin, the shallower the lesions, the more vigorous the metabolism, and the stronger the absorption capacity, the fewer the number of boils required. Generally, two to four boils are needed, each one takes about ten to twenty minutes, and the interval between two boils is three to six months. After the boils are treated, care should be taken to keep the wound clean and dry, and topical antibiotic ointment should be used to prevent infection. The newborn skin is more red and tender, so care should be taken to avoid prolonged exposure to the sun and careful use of cosmetics, etc.
V. Contraindications.
1, pregnant women.
2.People with photosensitive skin.
3.Patients with diabetes.
4.People suspected of having skin cancer.
5.Keloid patients.
The outstanding feature of laser treatment for nevus of Ota is that the treatment can be done without local anesthesia, in a few minutes to tens of minutes, and the operation is very convenient. The patient and the operator need to protect the eyes during the treatment, and the inflammation will subside in 4-6 days after the treatment with antibacterial ointment on the trauma. The depth of the lesion is directly proportional to the number of treatments, usually requiring 3-5 times, or 2-3 times for lighter colors, and more than 6 times for very heavy ones. The final result of treatment is ideal, with high success rate, not only no scar, but also no change of skin texture. Laser treatment is undoubtedly the ideal choice for nevus of Ota treatment.
VI. Precautions.
1.Keep the treatment area clean and avoid infection and friction.
2. If there are scabs on the treatment area, they should fall off by themselves, do not remove them by hand, otherwise pigmentation will be serious and scars will be easily left.
3.After the scabs fall off, there may be transient local pigmentation.
4. Pay attention to sun protection.
VII. Care before and after treatment
Wash the facial skin carefully before treatment. Avoid sunlight as much as possible after treatment, do not touch water in the treatment area, and use antibiotic ointment to prevent infection. Do not take aspirin-type drugs for a period of time after treatment, so as not to affect the recovery of the skin. Do not pack change drinking alcohol or eat irritating food for a week.