Ota's nevus is a common pigmented birthmark in the eastern nationalities, which is characterized by blue-brown spotted nevus around the eyes (although sometimes it does not necessarily appear at birth). In China, patients with nevus OTA account for about 0.4% of dermatology clinics and 2.6% of plastic surgery clinics, and the ratio of male to female is 1:3. About half of the patients found the disease at birth, but some patients began to find it in childhood, and only a few patients gradually appeared in adolescence, showing plaques composed of brown, gray and blue spots. The boundary of the lesion is unclear, and the spots in the lesion can be monochrome or both, with different colors. Due to the different density and location of melanocytes in dermis, plaques can appear light brown to dark blue, and different parts of the same lesion can appear different colors. The pathological changes of some patients have a tendency of gradual aggravation. Plaque occurs in forehead, eyes, cheeks and zygomatic region, which is equivalent to the distribution area of trigeminal nerve I and II, and can occupy all or part of this area. Plaque can occur on one side of the face, occasionally on both sides of the face, often symmetrical on both sides, and some melanocytes are also distributed in conjunctiva, cornea and retina. Ota nevus can grow slowly in the early stage, but the self-limitation of growth is difficult to determine. Some patients begin to be stable for a long time in childhood, and most experts think that they will be stable after puberty, but some people still have a slow growth trend until they are about 30 years old. Ota nevus has no genetic tendency and has no clear relationship with malignant transformation.
Ota's nevus and Ito's nevus, also known as brown-blue nevus of the upper jaw, are blue-brown patchy lesions that affect the sclera and facial skin innervated by trigeminal nerve.
【 Etiology and Pathogenesis 】 The nevus of OTA may be autosomal dominant inheritance, but some scholars hold different opinions. The skin lesions of Ota nevus are mostly distributed in the first and second branches of trigeminal nerve, and Ito nevus is distributed in the innervation area of posterior supraclavicular nerve and lateral brachial nerve. According to the characteristics of nerve distribution, it is speculated that melanocytes may originate from local nerve tissue.
【 Clinical manifestations 】 Ota nevus and Ito nevus are common in colored people, such as Oriental and black people. Women are more common. The lesions are pale cyan, grayish blue, brownish blue to bluish black or brownish yellow patches or spots. The color of the center of the plaque is dark, and the edge gradually brightens. Occasionally, some areas of pigment patches may bulge, or even appear small nodules the size of millet to mung bean. The spots are distributed in clusters with different densities, or the center is a patch and the edge is a spot. The color of skin lesions is aggravated by sun exposure, fatigue, menstrual period and pregnancy. Some adolescence will deepen and expand. The most common sites involved in this disease are periorbital, temporal, frontal, zygomatic and alar, which is equivalent to the distribution of the second and second branches of trigeminal nerve. Unilateral distribution, even bilateral (about 10%), about 2/3 of patients have the same sclera stained blue, and conjunctiva, cornea, iris, fundus, optic papilla, optic nerve, retrobulbar fat and periosteum can also be involved. Extensive skin lesions can also involve scalp, ear and neck, trunk, upper and lower limbs and other parts. Oral and nasopharyngeal mucosa can also be involved.
Ito's nevus belongs to the category of Ota's nevus, but their clinical manifestations and pathological changes are completely the same, mainly distributed in the areas dominated by the posterior supraclavicular nerve and the lateral arm nerve, such as the shoulder, neck and supraclavicular area, and some cases may be accompanied by ipsilateral or bilateral Ota's nevus.
[Diagnosis and differential diagnosis] According to the color, distribution and eye involvement of pigment, a diagnosis can be made. It should be differentiated from Mongolian spot and blue mole. Mongolian spots are born and can fade naturally. And doe not affect eyes and mucous membrane. In the tissue image, the number of melanocytes in dermis is less and the location is deeper. Blue nevus is a blue-black papule or nodule, which usually occurs on the back of hand, instep, face and buttocks. Melanocytes in tissue images gather together.
American Park Jung Su C3 laser therapeutic instrument produced by American Kangao Company. Using laser frequency conversion technology, various pigments can be quickly absorbed and broken into fine dust, thus achieving the effect of eliminating tattoos, spots and various birthmarks.
In recent years, the development of laser technology has brought the treatment of nevus of OTA into a new period. Tianda Medical Beauty Hospital currently uses Medlite c3 dual-wavelength dye therapeutic instrument (Q-switched laser) imported from the United States, with wavelengths of about 1064 and 755 nm. The melanocytes were destroyed by relatively selective photothermal action, which led to the rupture of melanosome and low function in the formation stage of melanosome I and II, and the ruptured melanosome was swallowed by phagocytes. Its outstanding feature is that it does not need local anesthesia, and the treatment can be completed in a few minutes to dozens of minutes, and the operation is very convenient. The final treatment result is ideal, the success rate is high, there is no scar and the skin texture has not changed. The effect and frequency are related to the pathological types of nevus of OTA. Although there are many treatment methods, laser treatment is undoubtedly the ideal choice for the treatment of nevus of OTA.
In order to achieve the ideal effect, it usually takes 3-7 treatments with the interval of more than 6 weeks, and each treatment can be completed in a few minutes to dozens of minutes. The patient felt that the skin was slapped by pulsed light beam, and the pain disappeared quickly after operation. The frequency of treatment is most closely related to the characteristics of lesions, followed by the above laser wavelength. According to the distribution law of melanin particles in melanocytes observed by microscope and naked eye, when cells are distributed in the superficial dermis, they are often light brown or brown, and when they are distributed in the deep dermis, they are blue or grayish black. The shade of the same color is related to the distribution density of melanocytes. This rule is very practical in judging prognosis and treatment times. Applicable to all types of nevus of OTA except sclera and conjunctiva.
Taboo:
1, pregnant women;
2. People with sensitive skin;
3. Diabetic patients;
4. Suspected skin cancer;
5, scar physique.
The outstanding feature of laser treatment of nevus of OTA is that it can be completed in a few minutes to dozens of minutes without local anesthesia, and the operation is very convenient, and the interval between each treatment is 3-6 months. Patients and operators need to protect their eyes during treatment. Antibiotic ointment was applied to the wound after operation, and the inflammation subsided in 4 ~ 6 days. The depth of the lesion is directly proportional to the number of treatments, generally 3-5 times, 2-3 times in light color, and more than 6 times in very heavy cases. The final treatment result is ideal and the success rate is high. Not only is there no scar, but also the skin texture has not changed. Laser treatment is undoubtedly the ideal choice for the treatment of nevus of OTA.
Precautions:
1. Keep the treatment site clean to avoid infection and friction.
2. If there is a fool's skin on the treatment site, it should fall off by itself. Do not remove it by hand, otherwise the pigmentation is serious and it is easy to leave scars.
3. After the scab skin falls off, there may be temporary pigmentation locally. In order to prevent or reduce this situation, sunscreen products can be used reasonably.
4. Pay attention to sun protection.
Frequently asked questions:
1, Q: Will it hurt during the treatment?
A: Laser is a pulsed light source. When the pulsed light source touches the skin, it will be as painful as being hit by a rubber band. After treatment, the treatment area will feel like a slight sunburn. After about a day, any discomfort will disappear, and the treatment area may appear red for two to four weeks. After the redness disappears, the skin will return to its natural and smooth color and tissue structure.
2. Q: How many times do you usually need treatment? How often do you do it?
Answer: It usually takes 3-5 times, light color can also take 2-3 times, and heavy weight needs more than 6 times. Treatment every 3-6 months.