Scar tissue is a natural product of the body’s trauma repair process. There are two types of trauma repair: one type is superficial wounds of the skin, affecting only the skin, initiated by epithelial cells of hair follicles and sebaceous glands and healed by simple epithelial formation. The repair can all achieve complete restoration of structural integrity and skin function; the other type is an injury deep to the dermis and subcutaneous tissue, which is repaired by scarring. I. Definition of scar Scar Scar is a collective name for the appearance morphology and histopathological changes of normal skin tissue caused after various traumas. Scar is a kind of inevitable result of wound healing after human trauma, which is the result of excessive proliferation of collagen fibers due to the loss of normal control of collagen anabolic function during the healing process of skin injury, also known as connective tissue hyperplasia, which is called crab foot swelling or giant scar in Chinese medicine, manifesting as benign lumps with different shapes, red color and hard texture that bulge out of normal skin. Classification of scarring Scarring can be classified according to pathology, morphology, function, symptoms, stability, nature, etiology, location and depth, and is described below mainly in terms of pathology and clinical manifestations. III. Pathological classification Usually classified into normal skin scar, proliferative scar, atrophic scar, keloid scar, scar cancer, etc. (a) Normal skin scar (flat scar) Pathological manifestations: the epidermis has only a few layers of epithelial cells, called scar epidermis. The deep layer is dominated by thickening of collagen fibers, without structures such as elastic fibers, hair follicles, dermal papillae and glands. In the early stage, there are more cells and vascular components, and collagen fibers are arranged without order; in the late stage, there are fewer cells and vascular components, and collagen fibers are arranged in parallel and regularly. (B) Proliferative scar The epidermis of proliferative scar is still several layers of epithelial cells, sometimes visible as keratinization or cell proliferation, without skin pegs. The dermis is thickened collagen fibers, irregularly arranged, with a large number of fibroblast infiltrates and mucopolysaccharide deposits. Collagen fibers in their normal state are seen beneath the hyperplastic scar separated from the subcutaneous tissue. (iii) Atrophic scar The pathological features of atrophic scar are: extremely thin epidermis, hyperkeratosis and thickening of the stratum corneum, obvious changes in the structure of the compound flat epithelium, reduction in the number of spiny cell layers, disappearance of the papillary layer of the dermis, disappearance of skin accessory structures such as hair follicles and glands, and hyperplasia of the subdermal connective tissue, mainly composed of collagen fibers and also deposits of mucopolysaccharides. The reticular layer is thickened. (iv) Keloid scars The manifestations of keloid scars: epidermal atrophy, sparse dermal papillae, normal epidermis, abundant dermal papillae, clearly visible skin appendages, large number of fibroblasts in early stages, focal aggregates of plasma cells, mast cells or very few lymphocytes. The nuclei of cells with difficult staining were more common, and a detached phase was visible. Fibrous tissue was closely arranged but swirling large nodules were less frequent. In the later stage, dense collagen fibers with irregular orientation and continuous sclerosis or glassy hardening are seen, cells can disappear, and collagen fiber bundles form dense large nodules. Specially stained areas in the nodule area usually lack elastic fibers, are swirled, have abundant mucinous stroma, and are clearly demarcated from the surrounding skin. (E) Scar carcinoma The pathology of scar carcinoma is mostly squamous carcinoma, and a few of them are basal cell carcinoma. Post-burn scar carcinoma is mostly squamous carcinoma, and radiological carcinoma is mostly basal cell carcinoma. The degree of differentiation of scar carcinoma is usually higher, and it is mainly manifested as local infiltration. Clinical classification of scar (a) Superficial scar or flat scar Superficial scar is formed by mild abrasion of the skin, or due to superficial second-degree burn, or superficial infection of the skin, usually involving the epidermis or dermis surface layer. Clinical manifestations: the scar is rough but flat and soft in appearance, sometimes with pigmentation changes, without functional impairment, and does not require special treatment. (2) Strip scar or contracture scar Most of the strip scars or contracture scars are flat and strip-like, a few of them are uneven or unevenly healed in a step-like manner, most of them are non-functional, but when the scar crosses the joint, it can cause dysfunction, and in severe cases, it can form hyperplastic scar. It is common in trauma or surgery. It can also cause functional impairment. (c) Webbed scar The scar is webbed and resembles a duck web, usually on the flexor side of the joint. It can also be seen at the openings of tubular organs on the body surface, such as the corners of the mouth, nostrils, urethra, and vaginal opening. It is mainly due to striated trauma across the flexor side of the joint. Webbed scars are caused by long narrow strip wounds or longitudinal linear wounds that cross the flexor side of the joint vertically, or by linear wounds along the free edge of the canal opening on the body surface, and the healed scar ends gradually shrink toward the center. With the shortening of the scar, the deformation of the joint flexion occurs, and the scar at the free edge of the canal opening changes from an arc to a straight line, and drives and pulls the elastic loose skin and subcutaneous tissues on both sides of the scar and its stroma to move and displace away from the flexion of the joint and toward the center of the canal, gradually forming a crease surface and becoming a webbed scar. Burn injury is the most common cause of webbed scar formation. (iv) Depressed scar The surface of depressed scar is significantly lower than the surrounding normal skin. It can be divided into two conditions: superficial depressed scar and deep depressed scar. The former is mostly asymptomatic and dysfunctional, while the latter severely affects the aesthetics and is mostly associated with functional impairment. It is usually caused by the healing of skin, subcutaneous tissue or deep tissue trauma. (E) Atrophic scar Atrophic scar has a flat and smooth appearance, level with the surrounding skin or slightly lower, and may show hypopigmentation or hyperpigmentation changes. The texture is tough and soft, with a loose matrix that can be lifted and pinched. These scars are mostly found on the face and chest and back and are generally more stable and do not cause functional impairment. Most of the scarring is due to superficial skin injuries, such as superficial second-degree burns, and occasionally deeper skin injuries, such as deep burn wound healing. (F) Bridge scar and superfluous scar The two ends of the scar are connected to the surrounding skin by the tip, and the lower channel is separated from the stroma, which resembles a bridge. It is often seen on the eyelid, jaw and anterior neck. They are usually multiple. Although the scars are short and rarely have functional effects, they are undulating and uneven, which is aesthetically displeasing and difficult to wash and keep clean, and can easily cause infection. Bridging scars and superfluous scars are often due to septic or atopic infections of the skin tissue. The formation of a subcutaneous cavity with spontaneous multiple breakdowns, or the subcutaneous trauma at the top of the subcutaneous cavity and the basal trauma of the cavity after drainage by several incisions, each healing successively in different times. (vii) Proliferative scar Proliferative scar is protruding from the skin surface, irregular in shape, uneven in height, flushed and congested, solid and tough in texture, accompanied by burning pain and scratching. Hyperplastic keloid scars are usually found in wounds with depth of injury only reaching the dermis, such as deep second-degree burns and wounds in the donor area where thick medium-thick slices are cut, etc. Occasionally, they are also found in deeper wounds and surgical incisions, with the possibility of self-regression and softening. The symptoms are aggravated by increased ambient temperature, emotional stress, or the consumption of spicy and irritating foods. Proliferations often continue for months or years before progressive degenerative changes occur, manifested by a decrease in protrusion height, darkening, decreasing congestion, and softening. Some can eventually flatten out and the pain and itching symptoms are greatly reduced or disappear. Local and systemic factors are common. Local factors include foreign bodies, inflammation, and pulling. Systemic factors such as young adults, women, especially pregnant women and patients with hyperthyroidism are prone to hyperplastic scarring, while rarely seen in the elderly, which may be related to the high secretion of estrogen and pituitary endocrine. In addition, race, genetics, and physical fitness are also associated with scar proliferation, but the exact mechanism remains to be further studied. (Most keloid scars usually occur 1 year after local injury, including surgical procedures, lacerations, tattoos, burns, injections, animal bites, inoculations, acne, and foreign body reactions, and have a strong and persistent proliferative force. The lesions are protruding from the skin surface, uneven in height, irregular in shape, hard and tough, with crabfoot-like infiltration to the surrounding sound skin and unbearable itching. The lesions are more likely to occur in the sternal stalk, shoulder deltoid, auricle, upper back, etc. 5.Keloid carcinoma may start as papule-like nodules on the scar with itching sensation, and later increase in size and rupture to form malignant ulcers, which are characterized by thickening of ulcer edges with keratinous hyperplasia or papilloma-like changes. They are characterized by thickening of the ulcerated edges with keratosis or papilloma-like changes. They mostly occur in contracture scars caused by burns, often in the vicinity of joints. There are many drugs used to prevent and treat proliferative scars and keloids. The main ones that are commonly used in clinical practice or have been studied are: corticosteroids, peptide growth factors, anti-free radicals, calcium channel blockers, retinoids, enzymes, anti-tissue gums and Chinese medicinal preparations. 1.Corticosteroids Adrenal corticosteroids include: glucocorticoids, salt corticosteroids, nitrogen corticosteroids and other types. These hormones are widely used in clinical practice, among which glucocorticoids have anti-inflammatory, anti-viral and anti-shock functions, and have obvious anti-tissue fibrosis effects. Deferiprone A, also known as tretinoin acetate, is a corticosteroid commonly used for intra-disease injections. After injected into proliferative scar tissue or keloid, deferox-A, on the one hand, inhibits collagen synthesis and aminoglucan production by causing down-regulation of mRNA in fibroblasts and reduces excessive accumulation of extracellular matrix; it can reduce the inflammatory response in the injured area. It can reduce the proliferation of fibroblasts; it can also reduce TGF-β and IGF-1 in the injured area, and make the hydroxyproline content in the scar tissue decrease. On the other hand, it reduces the amount of collagenase inhibitor-α macroglobulin, enhances the activity of collagenase and accelerates the breakdown of collagen, resulting in the thinning of the epidermal layer of the scar tissue, flattening of the dermal papillae, absorption of the matrix, and reduction of the collagen fiber gap. This results in a therapeutic effect. Retinoic acid is an intermediate product of vitamin A metabolism in the body, and is a vitamin A related drug, which includes retinoic acid, retinoic acid and retinyl ester. It can reduce local inflammation, promote epithelial cell growth, reduce collagen synthesis, reduce DNA synthesis in fibroblasts, and inhibit cell growth. The greater the concentration of retinoids, the more pronounced the growth-inhibiting effect. DaIy et al. treated 14 keloid patients with retinoic acid cream for 3 months and showed some efficacy. It is more effective when used in combination with deferiprone. The mechanism of calcium channel blockers in preventing keloid growth is that they regulate intracellular calcium concentration by blocking calcium channels, which in turn affects the synthesis of cell cycle mRNA. Kim et al. Lee et al. administered 0.1-0.5 mol/L topical injections of isoptin hydrochloride to the volume of scar tissue. The results were good with 3 injections at 3-week intervals. 4. Trinostat (cinnamon aminolevulinic acid) Trinostat is an H1 histamine antagonist, which can inhibit the release of histamine from mast cells, inhibit the proliferation of fibroblasts, and exert anti-scarring effect. Shigeki et al. used iontophoresis to penetrate the scar, which is significantly better than the oral method in reducing the itch and pain of patients. 5.Anti-tumor drugs 5~Fluorouracil (5~FU ) are anti-tumor drugs, they can inhibit cell division, stop cell growth, inhibit the secretion of collagen precursors and collagen cross-linking, and are used by many scholars for the treatment of scarring. Uppal’s study of 5-Fu soaked wounds for 5 min after excision of lesions in ll keloid cases, and tissue was taken for postoperative testing. 5-Fu treatment showed lower fibroblast activity and TGF-β1 content compared to the control group. No lesion recurrence was seen in the five cases followed up for 6 months after surgery. Fitzpatrick has injected 5-Fu into the lesions of more than 100 keloid patients, with a total of more than five injections. The interval between injections ranged from 2 to 3 times per week to once every 2 to 3 weeks and was considered effective, but comparative observations and follow-up data for more than 1 year were lacking. 6.Silicone gel film for scar treatment (II) Bioactive factors In the process of wound repair and scar proliferation, there are various bioactive factors involved and influence the process. The most closely related peptide growth factors are many: among them, TGF-β, bFGF, PDGF, EGF, IGF-1 and other factors have the effect of promoting scar proliferation in different degrees while promoting wound healing; while TNF, IL-1, IFN-γ and so on have the effect of inhibiting scar formation. (Linares et al. reported that the capillaries in the scar tissue decreased after compression therapy. Collagen fibers are arranged in parallel and fibroblasts and myofibroblasts are reduced. It is indicated for patients with large proliferative scars or those who are not amenable to radiotherapy or local drug therapy. As an adjunct to radiotherapy and drug therapy, it can reduce the recurrence rate and reduce the dose of radiotherapy or drug therapy. (iv) Radiation therapy for scar From the available research and treatment results, radiation has an obvious inhibitory effect on the proliferation of scar. The main types of radiation are x-rays and beta-rays. The biological effects are divided into direct and indirect effects. The direct effect is that the energy of radiation is directly absorbed by DNA or other molecules, causing chemical changes in biomolecules; the indirect effect is that the energy is transferred to biomolecules, acting through diffused ions and free radicals, and is absorbed by biomolecules to produce biological effects. It has been shown that radiation has a significant inhibitory effect on fibroblast division, proliferation and collagen synthesis, while it has a promotional effect on collagen degradation. Surgical treatment of scarring mainly includes laser therapy. What are the drugs used in the pharmacological treatment of scar? II. Surgical treatment of scar The treatment of scar surgery mainly includes: scar release implantation, laser therapy, application of fillers, etc. (a) Biological principles of laser treatment for scar 1. The effect of laser on hyperplastic scar and keloid Laser destroys tissue cells through its photothermolysis effect, causing capillary plexus to coagulate, resulting in tissue ischemia and oxygenation, releasing collagenase after granular cell lysis, and decreasing α2 macroglobulin content after blood flow decreases, which can indirectly enhance collagenase activity and increase collagen decomposition in scar tissue. In addition, the hyperthermal lysis of laser can break the collagen skeleton and promote the reconstruction of collagen structure, softening the scar and reducing its size. 2. Laser treatment for depressed scarring Most depressed scarring is the healing of acne, smallpox, blisters and other depressed scars of varying sizes and depths, which are traditionally treated by grinding. The principle of laser treatment is to use the strong thermal vaporization effect of the laser to vaporize the diseased tissue. During the vaporization process, one is the direct transformation of the body tissue into gas, and the other is the transformation of the water in the body tissue into water vapor. The laser vaporization method is easier and more thorough. Since the central part of the scar is depressed, the vaporization should be slightly deeper around the scar and slightly shallower in the central part. 3, Laser treatment of bridge scars Bridge scars are mostly seen in soft tissue infections that form a subcutaneous cavity, formed by the healing of the basal trauma of the cavity and the underlying trauma of the skin. Laser treatment of depressed keloid scars involves cutting off the tip of the bridging scar using laser focused cutting, and then cauterizing and vaporizing the wound to the normal tissue of the base using vaporization. Filler treatment can be used for depressed keloids. (B) Application of fillers Facial depressed keloids such as atrophic keloids, acne or smallpox caused by depressed lesions on the skin surface are difficult to treat and often difficult for patients to accept using skin abrasion, not to mention the possibility of erythema, hyperpigmentation and scarring. Therefore, filler therapy can be applied in many cases. The ideal soft tissue filling material should be: autologous material, which does not have immune rejection problems; can stay relatively long term, but not necessarily permanent, and the filling can be removed intact if necessary: painless. And easy to place; preferably can be placed by injection method; not expensive; less side effects, such as no skin redness, irritation, inflammation, migration, etc. And of course it cannot be toxic, teratogenic or even cause cancer. In the United States it must be approved by the Food and Drug Administration (FDA ) before it can be used. There are various materials used as fillers, the following are commonly used recently: bovine collagen, autologous collagen, Isolagen, Dermalogen, Artecoll, Resoplast, hyaluronic acid, Alloderm, Gore-Tex, Fibrel, autologous fat graft, etc. Comprehensive treatment of keloid scars The comprehensive treatment of keloid scars is mainly because the above-mentioned single method is difficult to achieve very satisfactory results for patients, and the combination of two or more methods is used to eliminate the functional or cosmetic effects as much as possible, commonly used are: surgery + compression + silicone film; laser + filling / perforation full-thickness skin grafting; grinding + topical drugs, etc. Any scar that affects the aesthetics and normal function of the human body needs to be treated. For example, linear, webbed, redundant, bridged, depressed, atrophic, and hyperplastic scars can be treated under the guidance of a doctor to improve the local appearance and function of the scar. There are many commonly used scar treatment methods, each of which has its indications, advantages and disadvantages, and an experienced plastic surgeon will choose according to your specific situation. Prevention of scarring At present, there is no specific treatment for scarring, so prevention of scarring is to some extent more important than scarring treatment. Research shows that the prevention of keloid scars mainly includes the prevention before the formation of keloid scars and the prevention during the formation of keloid scars; the main purpose is to remove as much as possible the factors that cause the proliferation of keloid scars, reduce the growth of keloid scars, and prevent the various hazards caused by keloid scars to the organism. I. Overview of scarring Scarring is the inevitable result of tissue repair when skin injury reaches the dermal reticular layer. Trauma repair is an extremely complex biological process that contains many cytochemical, immunological and molecular biological processes involving many factors such as multiple repair cells and cytokines. Broadly speaking, there is no scar formation and no wound healing, so it is not scientific to define keloid lightly. The main effects of keloid scars on the human body: bulging on the skin surface or accompanied by abnormal pigment metabolism, affecting the appearance; itching, pain and discomfort and other conscious symptoms; occurrence of contracture causing organ deformity and affecting the function of the body; can be followed by ulceration or even cancer. The purpose of prevention of scar: to prevent further deformation and functional disorders caused by scar, and to reduce the impact of scar on the body surface. Prevention before scar formation (a) Foresight for scar caused by primary injury The primary injury scar is mainly the scar caused by trauma and burns, which is often heavy and accompanied by different degrees of infection. Therefore, the focus is to prevent and control the infection, to create good conditions for wound healing, and to close the wound as early as possible. In the case of infection control, drugs such as growth factors can also be used to promote early wound healing, shorten the healing time and reduce scar growth. During the wound healing and repair period (within 3-4 months), try to eat less spicy and stimulating food to avoid stimulating the capillaries and collagen metabolism of the wound to produce scarring. In addition, steroid ointment applied at the early stage of scarring is also effective, but it is not effective for old scarring. Meanwhile, doctors should anticipate the chance of scarring and its inevitable occurrence according to the type of injury, which is important for guiding treatment and preventing medical disputes in the future. (B) Reduce the factors of scar formation during treatment The principle of treatment: love the tissue and reduce trauma. For this kind of scar formation factors are mainly caused by technical operation, the doctor in charge of treatment should be skilled in basic surgical skills, abide by the principles of plastic surgery, operate strictly aseptically, and for patients undergoing surgery should choose the appropriate time and adopt appropriate methods, and try to apply minimally invasive techniques to make them tension-free or low tension, foreign body-free and dead space-free. (C) Treatment of body surface wounds is the key to prevent scar formation For early fresh wounds, blood clots, foreign bodies and necrotic tissues should be thoroughly removed. Close the wounds as early as possible. For late contaminated wounds, the wounds should be thoroughly cleared, and drainage strips can be placed when closing the wounds, along with local or systemic application of antibiotics. For wounds with large tissue defects, tissue mobilization (flaps) should be adopted as early as possible to cover the wound and reduce granulation and scar tissue formation. In principle, the simplest surgical method should be used and unnecessary additional incisions should be avoided as much as possible, especially for patients with a tendency to keloid scarring. The scar formation period can be controlled by compression method and medication method. How to prevent before scar formation? Third, the prevention of scar formation period Although the scar has been formed, some measures taken at this time will still have some inhibiting effect on the growth of the scar, which can reduce the degree of scar formation and the harm caused by the scar to the organism. The prevention of scar formation period is to take effective measures to slow down the growth of the scar before the scar matures after the wound is healed, and to pass through the proliferation period to enter the maturation period and turn into a mature scar. The main methods are: compression therapy, drug therapy, radiotherapy and functional rehabilitation. At present, there are various methods to prevent keloid hyperplasia, but the effect is not the same. Most of the methods used are 2 to 3 methods with less side effects and easy to use. (a) Compression therapy The method of preventing and treating scar growth by continuous compression of the wound healing site with elastic fabric is called compression therapy. Since the 1970s, many medical centers have been using this method as the treatment of choice for the prevention of proliferative scarring after burns. Currently, the method is widely accepted as a routine method of preventing scar growth. It is one of the most definitive treatment options available. The principles of compression therapy are: one early (after the wound has healed), two tight (pressure of 2.0 to 2.4 kPa), and three long-lasting (pressure 24 hours a day except for bathing for 6 to 12 months). Compression therapy is mainly applied to hyperplastic keloid scars, especially those with large areas throughout the body, and can also be used as an adjunctive treatment after keloid surgery or radiotherapy. After the trauma surface is healed, compression bandages such as elastic bandage and elastic mesh sleeve should be used as early as possible, for example, splinting should be used to keep the joint in functional position, which can effectively reduce scar hyperplasia and scar contracture. Burn patients need to use elastic banding and other measures to apply pressure therapy to the skin graft area, deep II° wound healing area, and medium-thickness skin donor area. In general, after 2 weeks of compression therapy, the itchy and painful scar will be gradually reduced, and the scar will flatten in 1 month and soften in about 1 year. (b) Drug therapy In cases where compression is not suitable or scar growth is obvious, drug-assisted therapy should be used early. They can inhibit the synthesis of collagen by fibroblasts, promote the degradation of collagen and the transformation between type I and type III collagen, alleviate the symptoms and prevent or reduce scar proliferation. Topical medications The more commonly used are silicone gel patches and immunosuppressive topical rubs, such as keloid scar protectors (patches), mifepristal (HASF), retinoids, etc. Injectable drugs The more commonly used injectable drugs in the scar are corticosteroids, such as de-inflammatory pine, trimethoprim, compound betamethasone and other drugs, and some use colchicine and tumor necrosis factor (TNF). (c) Radiation therapy includes 90 Sr, 32P isotope dressing, X-ray and electronic ray irradiation, among which electronic ray irradiation is the best in terms of stable, controllable and safe dose. At present, it is mostly used for the prevention of recurrence after keloid surgery, and is advocated to be applied early after surgery, usually within 2 weeks, 1200-1500 rads. (iv) Comprehensive functional rehabilitation therapy is important to improve the quality of life of patients, including physical functional rehabilitation and psychological rehabilitation. Early sports therapy, maintenance of functional position and proper fixation, psychological guidance, etc. are mainly used. When the patient’s general condition improves, the wound begins to heal or completely heal, and there is a tendency of scar growth (especially when the scar location involves joint movement), slow active and passive activities such as joint flexion, extension, abduction, adduction, external rotation and internal rotation should be started two to three times a day. Various plastic splints, devices, massage and other therapies can also be used to keep the joints in a functional position and combat scar contracture, prevent limb dysfunction, and promote the recovery of the patient’s physical and mental health. It should be emphasized that this measure is often overlooked during this period, as patients tend to treat themselves at home. Doctors should carefully introduce the importance of these measures to patients or their families for the prevention of scar growth, and supervise and implement their effective implementation. (E) Physical therapy Applying various physical factors to treat the trauma in a timely and effective manner at the early stage of trauma can effectively prevent or reduce the proliferation of scar, and after the trauma is healed and the scar is proliferated, the application of physical factor treatment also has a better effect. Therefore, physical therapy for scar does not start only after the trauma is healed, but should start after the trauma and run through the whole treatment process until the patient recovers. Hot compress, ion introduction, ultraviolet radiation and electromagnetic therapy can be used to relieve scar symptoms and prevent further proliferation of scar. Prevention of scar proliferation The prevention of scar proliferation is to remove the factors that accelerate scar proliferation, reduce the growth of scar, and prevent the deformation and functional disorders caused by scar. If the scar has become a mature mass, it falls under the scope of treatment. The basic methods are the same as above. Compression therapy, pharmacotherapy, radiotherapy, functional rehabilitation, physical therapy, and avoidance of chronic stimulation (avoiding chronic stimulation such as friction and prolonged sunlight exposure can help reduce the proliferation of scar). V. Prevention after scar treatment The keloid is sure to recur after simple surgical excision, just as it did without surgery, so it cannot be treated with surgical excision alone. The preventive measures are largely the same as above. The surgical operation should comply with the principles of scar surgery: no tension, no cavity, minimally invasive incision, no residual blood clot, foreign body (including sutures), and early radiation therapy (currently, it is proposed that early radiation therapy should be given after scar surgery because the fibroblasts in the granulation tissue become fibroblasts within 24 hours, and theoretically, radiation therapy cannot wait until after the stitches are removed, but clinically, it is found that some patients are treated with radiation therapy after the surgery. However, it is found in the work that some patients delay the healing of the wound after radiation therapy, and in serious cases, it even leads to skin ulceration. There are different opinions on the time of starting postoperative radiotherapy, and now there is no prospective analysis stating the best treatment time), etc. The focus is that after the removal of the stitches of surgery, the wound should be treated with radiation and other adjuvant treatments in time, and local pressure or medication should be carried out in time when there are signs of recurrence. Scar prevention for patients with skin diseases When skin diseases such as folliculitis, acne and boils occur on the body surface, the local skin should be protected and not squeezed or scratched to avoid leaving depressions or proliferative scars, and strong stimulating and corrosive drugs should not be used indiscriminately. If the scar is continuously stimulated, it may lead to cancer. Prevention of scar cancer The prevention of scar cancer includes: pay attention to the protection of scar, avoid chronic stimulation and repeated injury; early treatment of ulcer wound and control of chronic infection; early surgery to remove unstable scar and chronic sinus infection. In conclusion, prevention of scarring requires a professional technical team, scientific theoretical guidance, advanced treatment equipment, comprehensive treatment measures and perseverance, because scar prevention and treatment is a systematic, long-term, and complex process that takes about 3 to 10 years, which requires sufficient patience, perseverance and adequate communication between doctors and patients. In addition, we should all be fully aware of the limitations of scar treatment, and it is difficult to obtain very satisfactory results in a short period of time. Scar revision can also only achieve some improvement because with each surgery, there is a new trauma. Therefore, taking various measures to maximize the prevention of scar formation is of equal significance to the treatment of scarring. It is believed that in the future, with the application of genetic technology and other developments, it can play a major breakthrough in the prevention of scarring. The treatment of keloid scars is very tricky and difficult to obtain very satisfactory results. Theoretically, once a scar is formed, even the most delicate surgical methods can only lead to partial improvement, but not complete eradication. Because every plastic surgery is a new trauma, taking measures to maximize the prevention of scar formation is as important as the treatment of scarring.