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KELOIDS AND HYPERTROPHIC SCARS

In recent years, along with the development of the social economy, aesthetic needs of people have increased. The number of patients coming to the hospital to treat keloids and hypertrophic scars is increasing.

Keloids and hypertrophic scars are characterized by local proliferation of fibroblasts and excessive collagen production during wound healing.

These two types of scars often occur after a skin lesion such as: skin cuts, tattoos, burns, shots, post-surgery, etc or skin abnormalities due to inflammatory processes such as acne, skin infections, and bumps. insect bites.

While hypertrophic scars usually appear within 6 months of injury, they are limited to the original wound and may regress on their own; keloids usually appear 6 months after the injury, go beyond the original wound boundary and never regress on their own.

Currently there are many methods used to treat keloids and hypertrophic scars. Treatment goals are based on each individual and the patient’s needs. Usually when the volume of scars decreases by 30-50%, symptoms that improve> 50% and / or achieve patient satisfaction are considered successful.

The treatments:

  1. Corticosteroids intralesion.

Mechanism: corticosteroids reduce collagen and glycosaminoglycan synthesis, inhibit fibroblast proliferation.

Indications: This method works best with active scars (redness, itching or pain).

  • hypertrophic and keloid scars
  • combination with cryotherapy
  • corticosteroids after surgical removal of keloids / hypertrophy.

Dosage: maximum dose: 5 mg / cm2, pure or diluted with 0.9% NaCl or lidocaine at a ratio of 1: 2 or 1: 4.

Side effects: pain during injection, atrophy of the subcutaneous tissue, vasodilation, then pigment, sediment white crystals at the injection site.

The method has a relatively high response rate: 50 – 100%, recurrence rate 9 – 50%.

  1. Interferon:

Mechanism: Interferon alpha and gamma inhibit collagen synthesis of types I and III through the elimination of intracellular ribonucleic acid.

Dosage: 1 million units / cm injection of skin around the postoperative area, after surgery and 1-2 weeks later.

Side effects: expensive, flu-like symptoms.

Often used as a combination treatment.

  1. Bleomycin

Mechanism: Decreases collagen synthesis by inhibiting TGF – β1 and lysyl oxidase

Dosage: 1 time/ 1 month, maximum 4 times, bleomycin 1.5 UI / ml. Injection 2ml / cm2 skin lesion, not exceeding 6ml / injection.

Side effects: hyperpigmentation, skin atrophy (rare). Less systemic effects.

  1. Cryotherapy

Mechanism: the cold action on microcirculation causes changes such as thrombosis, cell death due to continuous anemia.

The most commonly used substance is liquid nitrogen.

Side effects include pain during injection, depigmentation.

Response rate 62.5%. Hypertrophic scars respond better than keloid scars.

  1. Surgery

Mechanism: stretching the scar, cutting the spiral between the tension of the scar and continuing to increase scar thickness by stimulating continuous collagen production.

Indications:

  • hypertrophic scars lasting more than 1 year or less than 1 year if affecting function and aesthetics
  • hypertrophic scars lasting less than 1 year if affecting function and aesthetics
  • Large keloid, small bottom
  • keloid failure with other treatments.

Two commonly used techniques are W – plasty and Z – plasty.

Side effects: surgical site infection, flap necrosis or patch patch, Greater scarring before surgery. The relapse rate is high, 45 – 100%, often combined with other treatments to reduce the recurrence rate.

  1. Abrasive laser: CO2 laser, Er: YAG laser

Mechanism: causing evaporation of water (CO2 laser) or resection of organization (Er YAD laser).

Indications: hypertrophic scar is no longer active. Single treatment is not recommended with keloid scars.

Side effects: abrasion, oozing, crusting and persistent redness, Pigmentation changes after treatment.

  1. Non-invasive laser: PDL (585nm or 595nm)

Mechanism: coagulation, necrosis of small blood vessels, causing regression of scars.

Improve about 50 – 80% after 2 treatments. Rarely used.

  1. Other methods: injecting botulinum toxin A, pressure treatment (usually applied to the ear), radiation therapy, silicone and silicone gel patches, topicals, etc. These methods give low effectiveness.

Thus there are many methods that have been used to treat keloids and hypertrophic scars. For keloid scars, generally the methods have good response rates, but high recurrence rates. Many methods are still in the process of research and testing, promising new directions in the future.

Author: Dr. Trần Thu Hà Phương.

Publisher : Social work department