A keloid, commonly known as a scar, is an overgrown abnormal scar tissue formed after the healing of a skin wound or an unexplained skin injury. The keloid is a skin injury.
The keloid is a result of the loss of normal control of collagen anabolic function during the healing process, resulting in excessive proliferation of collagen fibers, also known as connective tissue hyperplasia, or in Chinese medicine as crabfoot swelling or giant scarring.
Clinical manifestations
It is a persistent lump that grows above the surrounding normal skin and beyond the original injury site, which is hard and inflexible, with localized itching or pain. The lesions vary in size from 2 to 3 mm papule-like to large palm-like flakes. The morphology is diverse, ranging from flat, symmetrical protrusions with regular margins to uneven, high-low masses with irregular protrusions, sometimes resembling crab feet with infiltrative growth into the surrounding tissue (also called “crab foot swelling”). The surface is an atrophic epidermis, but the epidermis of keloids in the earlobe can be close to normal skin. Most cases are solitary, but a few cases are multiple. The keloid develops rapidly within a few weeks or months after the injury and can grow continuously and continuously or remain stable for a considerable period of time. Inflammatory necrosis may occur within the lesion due to residual follicular glands or liquefied necrosis due to central ischemia. The keloid does not generally undergo contracture and does not generally cause functional impairment, except for a few joint sites that cause mild restriction of movement
Keloid scars can be broadly classified into two categories: primary and secondary. Primary keloid scars, mostly on the front of the chest or behind the shoulders, start as small red dots with itching and gradually change from small to large, soft to hard, red or dark red, and can be cord-like, butterfly-like, round, or irregular in shape. Secondary keloids are also called hyperplastic keloids. Most of them are caused by burns, trauma, acne, infection and septicemia, or after surgery, laser, freezing, implants, or hormonal medication, causing excessive proliferation of damaged tissues and degeneration of subcutaneous tissues, protruding from the skin, red or dark red with itching or stinging, and some of them have obvious outwardly extending capillaries.
Treatment
There are several methods of treatment for keloid scars.
1. Radiation therapy: It can shrink and soften the scar. However, it is rarely used at present due to its side effects.
2. Laser treatment is suitable for flat keloid scars without obvious dysfunction, scattered depressed keloid scars of different sizes and heights left after the healing of smallpox, chickenpox and acne.
3. Treatment with glucocorticoids: Topical skin disease patch is very suitable for small plaque keloids, which can achieve itching and pain relief, softening and shrinking the scar. Similarly, glucocorticoid ointments or creams can be used to seal the package. Trimethoprim suspension is injected within the lesion, focusing on the anterior aspect of the crabfoot swelling to stop it from extending outward. Injections can be made with pure tretinoin suspension or diluted with lidocaine, or with Depo-Provera injection, which is required to be injected within the scar tissue.
4. Treatment with drugs:Oral trinostat is effective in the treatment of keloid scars. Trinostat has an inhibitory effect on fibroblasts. The treatment of keloid requires an increased dose and more than half a year of continuous oral administration, which firstly relieves itching, pain and thinning of the scar with few adverse effects. There are reports from abroad that topical interferon gel to treat keloids has better efficacy. Chinese herbal medicine activates blood stasis and strengthens the spleen to relieve itching.
5. Surgical treatment
(1) Scar excision followed by reduction fine suturing is an increasingly sophisticated surgical method commonly used in the treatment of keloid scars and is mostly applied to keloid scars of small size. The clinical effect is determined by reducing the tension of the incision, fine operation and reducing secondary injury to reduce the degree of postoperative scar growth.
(2) Dermabrasion is a surgical method to grind the epidermis and superficial dermis of the skin in order to improve the irregular part of the skin surface and make it smooth and flat as well as similar in color. It is suitable for superficial scar left after acne, smallpox, chickenpox, herpes zoster, eczema, trauma, burns or surgery. If necessary, it can be performed simultaneously with surgical excision of the scar, and the effect is better than that of simple grinding.
(3) Scar release local reshaping surgery can be performed on small striped or webbed scars with tension, and then use the surrounding normal skin tissue to form a flap to repair the skin defect at the scar site by cross transposition.
(4) Scar excision free skin grafting Larger hyperplastic keloid scars can be surgically excised, and then free skin flaps can be cut from normal body parts and transplanted onto the scar wound to repair the wound and restore the skin function. However, the color of the transplanted skin often differs greatly from the surrounding skin, plus it is easy to contracture after surgery, pulling the surrounding tissues and organs to deform or cause dysfunction is its disadvantage.
(5) Scar excision flap grafting, because the flap contains more subcutaneous fat tissue, can be used to repair skin defects after scar excision, in addition to the role of protecting deeper tissues. Currently, the commonly used expander technique also belongs to flap grafting, by burying the expander under the normal skin around the scar, after several months of expansion, extra skin can be “grown” to repair the scar.
Other therapeutic effects of cryotherapy, waxing, iontophoresis, ultrasound, etc. on hyperplastic keloid scars and keloid scars have been reported with varying degrees of efficacy and lacking a large number of case controls and follow-ups.
Prevention
1. Strict aseptic technique for wounds, minimize second trauma to wounds, and promote early phase I healing of wounds.
2. Pay attention to the suturing of skin incisions, which must be performed without tension to obtain better results; otherwise, even if the incision heals smoothly, a wide and thickened scar tissue will still be produced gradually in the future.
3. Pay attention to the direction of the skin surgery incision. The skin surgical incision should be made in the direction of the skin grain, otherwise it will produce heavier scarring and unequal degrees of contracture and functional impairment.
4. When dealing with deep burns, the trauma should be properly treated to prevent or effectively control infection and promote early healing of the trauma. Perform skin grafting on [expression]° burn wounds as early as possible.
5. In the process of dealing with any trauma, if care is taken to avoid unnecessary surgical trauma, thorough hemostasis, application of fine instruments and materials, and early removal of sutures and other links, scar tissue is also often produced less frequently after the trauma heals.