Contracture scar

Introduction A contracture scar is a scar named after the dysfunction caused by it. More common after deep burn healing, due to scar contraction, often lead to shape changes and dysfunction, long-term scar contracture can affect the development of bones, muscles, blood vessels, nerves and other tissues, should be treated early. Skin grafting or other surgical treatment is generally used.

Cause

(1) Causes of the disease

Abnormal growth of scar tissue is closely related to many factors. Scar is an important component of the body's self-defense system. It is both the healing process of wounds and the inevitable result of healing. Healing goes through 3 stages.

1. Exudation stage: exudation of plasma, lymph, leukocytes, phagocytic cells, etc. in the wound. The autolysis process caused by phagocytosis, removal, absorption, etc., and enzymes assisted by damaged cells, removes necrotic tissue and contaminated bacteria, foreign bodies, etc., and the network formed by cellulose will form the surface layer and deep layer of the wound. Initially bonded together. Clinically, the local area of the wound is slightly red and swollen.

2. Collagen stage: After inflammatory exudation, proliferation of fibroblasts and capillary endothelial cells gradually appears. Fibroblasts are gradually polymerized to form collagen fibers with the participation of substances such as glycine, hydroxyproline, and hydroxylysine. Collagen fibers have a high degree of toughness, which increases the tensile strength of the wound. At this time, the skin has a reddish scar, slightly raised, hard and tough, and it has a feeling of itching.

3. Mature stage: Collagen fiber is continuously synthesized, and at the same time, under the action of collagenase, it is continuously decomposed. After about one month, anabolism and catabolism are gradually balanced. The fibroblasts are transformed into fibroblasts, and the collagen fibers gradually become neatly arranged in a bundle, the capillaries are occluded, the number is reduced, and the skin scars begin to undergo degenerative changes. Clinically, the scar is congested and the color is slightly darker than normal skin color, or slightly pinkish white. The scar is flatter than before, the texture is becoming more flexible, and the matrix is becoming looser.

In summary, the occurrence of keloids is related to "special physique", so there is a clinical description of "scarring physique". In the etiology, trauma, infection or inflammation, increased skin tension, local immune factors, endocrine factors, family genetic predisposition, etc. may be related to the formation of keloids, but a considerable part of clinical keloids occur on normal skin. No clear history of trauma.

(two) pathogenesis

So far, its pathogenesis is not fully understood. Recent studies have found that the expression of certain cytokines such as transforming growth factor B in keloids is increased, and the synthesis of extracellular matrix components such as collagen and fibronectin in keloid fibroblasts is increased (Fig. 1). It is speculated that under the action of certain cytokines or other mediators, the function of dermal fibroblasts to synthesize extracellular matrix is activated and the degradation function is reduced, thereby causing excessive accumulation of collagen-based extracellular matrix components in the dermis. And the onset.

an examination

Related inspection

Skin test skin color skin fungal microscopy

Clinically common deformities caused by scar contracture include valgus valgus, lip valgus, chest-thoracic adhesion, hand scar contracture deformity, and flexion or extension of the joints. Among them, the cord-like scar contracture in the flexion of the joint, for a long time, the skin and subcutaneous tissue on both sides of the contracture scar can gradually elongate, becoming a scar-like scar contracture, called a scar contracture scar. Such larger scars are common in the anterior neck, axillary fossa, elbow fossa, ankle joints, etc., and the smaller ones can be found in the medial malleolus, external malleolus, nasolabial fold, mouth, finger, etc. The opening of the body cavity is annular, causing its narrow diameter and affecting normal function.

Differential diagnosis

Attention should be paid to the difference between hypertrophic scars. The early two can not be distinguished, but there are significant differences in degree. Hypertrophic scars show excessive growth of connective tissue proliferation and hyaline degeneration, generally 3-4 weeks after injury. Occurred inside, at this time the scar ridges thickened, forming a clear plaque, reddish or red, with small capillary expansion, sustained or intermittent growth for several months to several years, forming an irregular appearance, sometimes like crab feet It usually stops growing after several months of growth, and the flushing disappears. There is still the possibility of natural degeneration. In addition, the fiber bundles can be fused and shrink and elastic fibers appear.

1. Hyperplastic scar: also known as hypertrophic scar or hypertrophic scar, is not qualitatively different from keloid in histopathology, only the degree of difference, so the difference between the two lesions is mainly depends on Clinical performance and other laboratory tests.

2. Sometimes it must be differentiated from cutaneous fibroids, scarring sarcoidosis, and histopathological examination can help to confirm the diagnosis.

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