Understanding the specific characteristics of each type of scar is important because each scar has different causes and care methods. For those who have problems with hypertrophic scars and keloid scars, this knowledge will help you choose the appropriate treatment method.
What are Hypertrophic Scars & Keloid Scars? How are they different?
Hypertrophic scars and keloid scars are scars caused by the wound healing process with excessive collagen production, but they have distinct characteristics as follows:
| Characteristic | Hypertrophic Scar | Keloid Scar |
| Scar boundary | Raised only within the original wound area, does not extend beyond the scar boundary | Raised and extends beyond the original wound boundary |
| Scar color | Red or pink, may fade over time | Red, purple, or brown, and may not fade |
| Symptoms | May have itching or mild pain initially but improves over time | May have itching, pain, and progressively enlarge |
| Chance of self-resolution | May shrink within 6-12 months, though some raised area may remain | Does not resolve on its own and may continue to grow |
| Main cause | Caused by inflammation or high tension such as surgical wounds or burns | Genetic factors and can easily occur even from small wounds such as ear piercings or inflamed acne |
| Common locations | Areas with frequent movement such as elbows, knees, shoulders | Areas with high tension such as ears, chest, shoulders, neck
and other areas such as jaw, clavicle, and mid-back |
| Treatment | May improve on its own or use silicone gel | Usually requires more intensive treatments such as steroid injections, laser, surgery combined with radiotherapy |
Besides hypertrophic and keloid scars, there are other abnormal scar types such as depressed scars, which are indentations or pits under the skin, or scar contractures that cause tightening of the tissue around the scar, such as scars from burns or scalds. Treatments vary depending on the type.
Why do some people develop keloid scars while others do not?
Although the exact cause of keloid scars is not clearly identified, several factors may influence the risk of developing keloids as follows:
- Genetics If family members such as parents or siblings have had keloid scars, the risk increases because the body tends to produce excessive collagen when wounded.
- Individual immune system which stimulates cytokine secretion and fibroblast activity to produce collagen in varying amounts.
- Skin color People with darker skin, such as African, Latin American, and Asian descent, are more prone to keloids than those with lighter skin, possibly related to melanin and inflammatory response of the wound.
- Hormones and age Especially teenagers, young adults, and pregnant women, during periods of high hormonal changes.
- Scar location Often occurs in areas with high skin tension or frequent movement such as chest, shoulders, back, ears, jaw, and upper arms.
- Type of wound Wounds with significant inflammation such as burns, deep inflamed acne, surgical wounds, tattoos, and ear piercings.
- Initial wound care Affects keloid prevention. Proper wound cleaning, preventing infection, and avoiding excessive tension or pulling on the wound reduce keloid risk. Conversely, slow healing, chronic inflammation, or frequent irritation such as rubbing or friction from clothing can stimulate keloid formation.
Keloid scar treatments that improve appearance
Although keloid scars are difficult to completely cure, several methods can reduce their size and improve their appearance. Treatment usually starts with non-surgical methods (Conservative Treatment), which can treat more than 95% of patients with this type of scar.
Conservative Treatment
- Using silicone gel sheets to cover the wound after it has healed for about 7 days. The sheet should be worn 24 hours a day for 3 months to increase moisture, reduce inflammation, and fade the scar.
- Microporous tape can be used instead of silicone sheets in some cases to increase moisture, reduce inflammation, and prevent raised scars.
- Intralesional steroid injection: Triamcinolone acetonide injections are commonly used to reduce inflammation and inhibit excessive collagen production. Injections can start as soon as the scar begins to show keloid characteristics, especially within the first 6 months for best results, typically once a month or depending on treatment response.
Medical Technology Treatments
- Laser therapy: Using lasers such as Pulsed Dye Laser (PDL) or Fractional Laser helps reduce redness and smooth the scar by destroying small blood vessels and stimulating skin regeneration. Multiple sessions are required, often combined with steroid injections for better results.
- Cryotherapy: Using liquid nitrogen to freeze and destroy keloid tissue helps the scar gradually shrink. It may cause pain during treatment and requires multiple sessions for optimal results.
Surgical Treatment
- Surgical excision: Usually used for large scars or scars unresponsive to other treatments. May be combined with steroid injections or silicone sheet coverage to reduce recurrence risk.
- Serial excision: Used for large scars where the surgeon removes the scar gradually in stages to reduce scar size progressively.
- Dermabrasion: Used for rough surface scars such as those from inflamed acne or chickenpox, helping to smooth the skin but carries a risk of darkening the skin after treatment.
Radiotherapy Low-dose radiation after surgery helps inhibit collagen production and reduce the risk of keloid recurrence. It is suitable for patients with large scars and frequent recurrences.
Treatment usually starts with silicone sheets, microporous tape, and steroid injections. If ineffective, medical technologies such as laser may be used. Surgery and radiotherapy are often last-resort options for large scars or when other treatments fail. Keloid treatment often requires a combination of methods for the best outcome.
Can keloid scars recur? How to prevent recurrence?
Keloid scars can recur. However, the risk of recurrence can be reduced as follows:
- Keep the wound clean and use medications as prescribed, such as topical treatments or silicone sheets to reduce inflammation and prevent raised scars.
- Avoid scratching or applying strong pressure on the scar to prevent re-injury.
- Use pressure therapy or pressure garments to control scar tissue formation, especially for large wounds such as burns or scalds. These should be worn continuously for 6 months to 1 year after the wound occurs.
- Scar massage with appropriate pressure, possibly combined with scar-reducing creams or gels, helps reduce scar expansion and soften the scar. Massage should be done regularly during the first 3-6 months after healing to stimulate blood circulation and reduce keloid risk.
- Steroid therapy: In some cases, doctors may recommend topical steroid use to help control scars long-term.
- Regular follow-up with a doctor to monitor treatment progress. If the scar shows signs of recurrence, early treatment should be started to prevent worsening.
Keloid scars can be treated and the risk of recurrence reduced with proper care and medically guided treatment. If you are concerned about keloid scars, you can consult at Phyathai Phaholyothin Hospital, which has expert doctors, standardized treatment protocols, and advanced technology to provide appropriate care. Consult us today for confidence in your scar treatment.
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Dr. Sikharin Sornpipatpong
Specialist in Laparoscopic Surgery and Obesity Surgery
Phyathai Phaholyothin Hospital
