1. Skin grinding for nevus of OTA

1) label: non-surgical, 1-2 grade.

2) technical principle

Grinding is used to treat nevus of OTA by controlled mechanical grinding of epidermis and superficial dermis. After grinding, when the wound heals, it can change the tissue structure of the skin surface and rearrange the collagen fibers and elastic fibers of the dermis. The remaining skin appendages (hair follicles, sebaceous glands, sweat glands) will quickly form a new epidermis, leaving almost no scars on the wound. For patients with severe nevus of OTA, it can not be completely removed, and it can be combined with skin freezing to improve the therapeutic effect.

3) Adapt to the crowd and taboo crowd

① Applicable people: It is suitable for the treatment of mild nevus of OTA.

② Taboo crowd

A. hemophilia or abnormal bleeding;

B. Patients with active infectious hepatitis;

C. emotional instability and excessive demands;

D. Keloid constitution, especially the prone parts;

E. For those with large and deep scars, hyperplastic scars and atrophic scars;

F patients whose skin lesions are suspected to be malignant or have been diagnosed as skin malignant tumors;

G. Local skin is obviously infected;

H those who have a history of radiotherapy or radiation dermatitis within half a year.

4) Cost: 200-600 yuan/time.

5) Technical methods

Subcutaneous anesthesia is needed before operation, and then polishing is carried out. In order to make the color of the whole face uniform, it is necessary to smooth the face. After grinding, cover it with vaseline gauze and thick gauze.

6) Skin grinding

Dermatodermabrasion, also known as dermabrasion, is the most commonly used method of medical cosmetic skin replacement technology in clinic. Grinding often uses a grinding head to grind the surface layers of epidermis and dermis in a controllable mechanical way. The repair mainly depends on basal cells in epidermis and spinous cells near basal layer, as well as residual skin appendages such as hair follicle wall, eccrine gland wall and sebaceous gland wall. When the wound is healed, the tissue on the skin surface can be changed, and the collagen fibers and elastic fibers in the dermis can be rearranged. The remaining skin appendages (hair follicles, sebaceous glands and sweat glands) will quickly form a new epidermis, leaving almost no scars on the wound surface, thus completing the treatment and cosmetic surgery. Ota nevus mostly occurs in dermis and dermis. Skin grinding has some limitations in the treatment of nevus of OTA, and it is effective for mild nevus of OTA, and can be combined with cryotherapy for severe nevus of OTA.

7) Risks and complications

① Pain: Most people have no pain or only slight pain after operation, so they can take general painkillers according to the doctor's advice.

② Edema: Sometimes slight edema appears after grinding, and usually disappears in 3-6 weeks.

(3) Skin redness: it is the first complication after grinding. Its duration varies from person to person and generally disappears within 1-3 months. ④ Miliary papule: It often occurs 2-6 weeks after operation and should be further treated in the hospital. ⑤ Scar hyperplasia: It can appear in any part of grinding, mostly women. Generally, mild scar hyperplasia can subside and flatten itself after about 1 year. If necessary, grind the skin after 1 year to flatten the hyperplastic scar.

⑥ Infection: The incidence rate is low, which is mainly caused by excessive wound pollution and improper postoperative treatment.

⑦ Pigmentation: The incidence rate is high, which generally appears around 1 month after operation, and the peak period is 2 months, mostly 6-1 February, and a few of them are over1year.

8) Course of treatment and recovery time

The outer gauze can be removed 5-6 days after operation, and the oily gauze can be removed 10 day after operation. After the first grinding, it takes 3 months for the second grinding.

9) Precautions

① Dermatization should not be done when there is folliculitis or acne on the face.

② Avoid direct sunlight after operation, and wear a mask or a wide-brimmed hat.

③ Don't put on makeup within two weeks after operation.

④ Pigmentation will remain temporarily, usually for 3-6 months, and at most 1 year can disappear by itself.

2. Treatment of nevus of OTA by chemical peeling.

1) Label: Non-surgical.

2) technical principle

Chemical exfoliation is to apply exfoliating drugs to the facial skin of nevus OTA and carry out controllable chemical treatment on the skin. After epidermal exfoliation and superficial tissue ischemia, scabbing and shedding, new, smooth and moist epidermal tissue is formed, thus achieving the purpose of treating nevus of OTA. Because nevus OTA mostly occurs in the dermis or subdermal layer of the skin, chemical peeling has certain limitations in the treatment of nevus OTA.

3) Taboo crowd

① Surgery has been performed in the operation area in the past 2-6 months, such as eye bag plastic surgery, wrinkle removal and liposuction.

(2) There are local bacterial and viral infections.

③ Patients with immune-related diseases.

④ Patients receiving radiotherapy.

⑤ Those who have recently received estrogen and progesterone therapy or are receiving isotretinoin therapy.

6 people with scar constitution.

7 mental illness or emotional instability.

8 Smokers or people who are taking oral anticoagulants have slow skin healing and are not suitable for chemical skin change.

4) Cost: several hundred to several thousand yuan.

5) Technical methods

Conventional skin disinfection, in the case of protecting the skin in the non-desquamation area, dipped in desquamation liquid and applied to the nevus of OTA, experienced the process of whitening, blackening, scabbing and shedding.

6) chemical stripping

The purpose of chemical skin exchange is to controllably destroy the skin at a certain depth by chemical reagents, start the repair process of adjacent epidermis and adnexal structures, form new epidermis and dermal upper layer, and promote the reorganization of dermal collagen, and replace the original imperfect skin with new skin. The occurrence of nevus OTA may be due to the fact that some melanocytes failed to cross the boundary between dermis and epidermis when moving to epidermis and stayed under dermis for a long time. In the middle dermis, melanocytes contain many different melanin particles, which are scattered between dermal collagen fibers. The therapeutic effect of chemical peeling on nevus of OTA has some limitations.