Keloid scar is a limited benign overgrowth of connective tissue that occurs more often after injuries, thermal and chemical burns of the skin, acne. The clinical picture is characterized by the formation of a dense, red scar roller, the presence of which is sometimes accompanied by itching, burning, and a local increase in temperature. Diagnosis is based on the clinical picture, anamnesis of the disease and differentiation with hypertrophic scars. Treatment of keloids includes glucocorticoids in various forms, cryo- and laser therapy, massage, compression dressings, interferons, surgical excision.
L91.0 Keloid scar
Keloid scar is one of the varieties of pathological scars, belongs to the group of pseudotumor fibromatoses. Of all types of scars, keloid is the second most common (after hypertrophic scar) among Europeans and the first among the population of South African countries. There are no exact statistics. This is due to the low number of patient visits to the doctor in the absence of progressive overgrowth and a pronounced clinical picture. Men are more prone to the formation of keloid scars, which is associated with an increased frequency of injuries, as well as persons with hormonal disorders.
The etiological factors of the occurrence of keloids are diverse. The main causes are surgical interventions, burns, but even a microtrauma can serve as a trigger for the appearance of a scar in predisposed individuals. The development of keloids is also promoted by some skin diseases (primarily acne), which occur with inflammation of the deep layers of the skin and rough scarring. Scar tissue is often formed at the sites of injections, tattoos, piercings, especially in the case of their complication by the suppurative process. Among the predisposing factors , the most important are:
- Heredity. The presence of a genetic predisposition is indicated by family prevalence (the tendency to form keloids is transmitted by an autosomal dominant type), a large number of reported cases of congenital keloids, as well as increased morbidity in people of African and Asian descent.
- Hormonal imbalance. In persons prone to keloid scarring, a violation of the functioning of the endocrine glands (thyroid, parathyroid, genital) is significantly more often detected. Corticosteroids have the greatest effect, so pathological scarring can often be observed in athletes who use anabolic steroids. The second most frequently affected hormone is progesterone – it is associated with an increase in the risk of keloid formation during pregnancy. Keloid scars are more often detected in people with dark skin, which makes it possible to associate their appearance with a violation of melanin synthesis.
The mechanism of keloid scarring has not been reliably established, however, it is known that keloid is the result of a violation of the process of normal skin regeneration. Keloid scar is characterized by the proliferation of dense connective tissue wider than the original boundaries of the wound. Apparently, this is due to the excessive production of type I collagen by fibroblasts and its excessive concentration in the scar area. During pathomorphological examination, wide hyalinized bundles of dull pink collagen are found in the scar tissue. There are a number of studies that prove the existence of a relationship between neuro–endocrine disorders and the frequency of keloid scars. Normally, as the scar tissue matures, angiogenesis decreases, but in keloids there is a constant formation of neovessels, which causes their hyperemia.
All scars are divided into normotrophic, hypertrophic, atrophic and keloid. The first three types are characterized by stage formation, a light color during the final transformation (the color of normal skin), a positive and good response to therapy. Keloid scar differs from other pathogenesis, rapid and uncontrolled growth, difficulties in treatment. In clinical dermatology , keloids are divided into:
- True (spontaneous). They are formed for no apparent reason, however, it is believed that they may be preceded by microtrauma, resolved pustular rashes. A favorite localization is the face and chest. True keloids often have a bizarre shape with branching processes extending from the main scar.
- False (scarring). They occur on the site of damaged skin after operations, cuts, burns, boils, acne. They do not have a specific localization. The shape of false scars is linear, the skin above them is prone to ulceration.
- Keloid folliculitis (keloid acne). It occurs in men. It is a follicular dermatitis of the scalp. Rashes (papules and pustules) are usually located in the back of the head.
According to the stage of development, keloids are divided into active (growing) and inactive. The active keloid is in the process of growth and causes symptoms such as itching, sometimes turning into pain, numbness, hyperemia. Inactive keloid does not grow and does not bother. According to the statute of limitations, scars are classified into young and old. Young scars are less than 5 years old, they have a red color and a shiny surface. Old scars are older than five years, their color is approaching the color of the skin, and the surface is uneven.
In the area of previous trauma or spontaneously there is a clearly limited, dense, bumpy growth of keloid tissue. The scar is bluish-red, thick, itchy. The skin covering the keloid is atrophic thinned, does not contain sweat and sebaceous glands, hair follicles and pigment cells, i.e. this area of the skin never tans, hair does not grow on it. Sometimes telangiectatically dilated vessels are observed.
Keloids are characterized by unstoppable growth and spread to healthy areas of the skin. Their growth begins after 10-12 weeks of healing, the area of scar tissue spread is much larger than the wound received. Spontaneous keloids are especially often localized on the face, neck, upper torso, in particular, in the sternum. The most typical complaints of patients with keloids are unpleasant sensations in the scar area: pain when pressing, hypersensitivity to various stimuli, annoying itching, sometimes turning into neuropathic pain.
As the depth and size of the scar increases, the likelihood of developing systemic disorders due to connective tissue hypertrophy increases. At the site of some wounds, pronounced contractures are subsequently formed, which have significant functional and aesthetic consequences. If there is a predisposition to pathological scarring, a new keloid may form at the site of the removed keloid scar, which rapidly increases in size and occupies an even larger area.
The diagnosis is not particularly difficult and relies on the clinic and anamnesis of the disease. From the basic laboratory data, the hormonal status and lipid profile are examined, which can be changed. Keloid scars should be distinguished from hypertrophic ones: the latter are usually thick, dense, white, with a bumpy surface, often with transverse cracks, which occur in the absence of a genetic predisposition after injuries or operations, unlike keloid scars, do not go beyond the primary defect. An important difference between hypertrophic scars is their response to treatment: surgical excision gives a stable satisfactory cosmetic result.
Keloid scar treatment
Keloids are difficult to treat. In order to determine the depth, prevalence and method of treatment, it is necessary to consult a surgeon and a dermatologist. A competent action plan, including the right choice of therapeutic tactics, consideration of predisposing etiofactors and emotional support, contributes to optimal results. The following types of treatment are used for keloids:
- Local drug therapy. Before the formation of a crust on the scar, healing ointments and creams based on panthenol can be used. After the formation of the keloid, a silicone cream is applied or a silicone patch is applied for several weeks or months. Silicone creates an air-permeable membrane that is favorable for skin regeneration. In the case of fresh keloids, remission can be achieved by locally applying glucocorticoids either in the form of ointments under occlusion, or (more effectively) in the form of intraocular injections of a crystalline suspension.
- Physical methods. Laser scar resurfacing is a widely used safe and painless method. Laser therapy reduces the size of the scar, relieves redness and prevents re-growth. With a convenient anatomical arrangement of the keloid, some regression can be achieved with the help of a compression bandage. Cryotherapy is used only in the treatment of small scars on closed areas of the body, because it is quite painful and causes depigmentation of the skin. Treatment with liquid nitrogen is carried out in several cycles (up to 5 sessions), more often used in combination with other methods.
- Scar massage. Limited dense keloid strands can be softened with regular massage. This type of treatment is most relevant in the joint area: as soon as the scar becomes stable (after 3-4 weeks), it is necessary to counteract the shortening of the scar tissue with massage. It is not used in case of infection and with progressive scar growth (more than 1 cm per week).
- Surgical treatment. It is recommended to refrain from surgical interventions, after excision of the scar, the formation of a new keloid most often follows, especially if healthy tissue is affected during the operation. Therefore, only partial excisions should be performed, and then injections of glucocorticoids or cryotherapy, sometimes X-ray irradiation.
- Special methods of treatment. In dermatology, treatment with interferons and radiation therapy is used in rare cases due to systemic effects on the body. Despite the fact that when using interferon, the keloid decreases in size, there is no information about the duration of the effect. Radiation therapy is used only when absolutely necessary, because it increases the risk of malignant neoplasms.
Prognosis and prevention
The prognosis depends on the volume and location of the scar, the state of the body (the presence of pathologies from the endocrine and nervous systems), predisposition to spread, rapid diagnosis and a competent combination of various types of therapy. Prevention includes prevention of burns, competent and early treatment of acne, sparing surgical incisions, possible restriction of injections and piercing. In the presence of this pathology in relatives, it is worth excluding the above factors and protecting yourself from all kinds of microtraumas that can serve as triggers in the development of keloid-type scars.