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Hypertrophic and keloid scars - causes and treatments

Table of Contents

Introduction
What Are Hypertrophic and Keloid Scars?
Symptoms of Hypertrophic and Keloid Scars
Causes of Hypertrophic and Keloid Scars
Risk Factors for Hypertrophic and Keloid Scars
Treatments for Hypertrophic and Keloid Scars – Overview
Conclusion

Introduction

Scars are a natural part of the body’s healing process, but in some individuals, the healing response becomes exaggerated, resulting in hypertrophic or keloid scars. These types of scars are not only cosmetically concerning but can also cause discomfort, itching, or pain. Unlike typical flat scars, hypertrophic and keloid scars are raised and may continue to grow long after the wound has healed.

Understanding the causes, symptoms, and treatment options is essential for managing these scars effectively. In this article, we’ll explore what sets hypertrophic and keloid scars apart, who’s most at risk, and the range of treatments—from topical therapies to laser and injectable options—that can help reduce their appearance.

What Are Hypertrophic and Keloid Scars?

Both hypertrophic and keloid scars involve an abnormal buildup of collagen in response to skin injury. However, they differ in appearance, behaviour, and treatment response.

Hypertrophic Scars

Raised, red or pink, and confined to the borders of the original wound.
May regress over time.
Common after burns, surgical incisions, or traumatic injuries.

Keloid Scars

Raised, thick, and often extend beyond the original wound margins.
It can continue to grow for months or even years.
More difficult to treat and often recur after removal.

In some cases, diastasis recti is purely cosmetic. However, for many, it affects functional movement and quality of life.

Symptoms of Hypertrophic and Keloid Scars

Both types of scars may present with:

Raised, thickened skin
Red, pink, or dark pigmentation
Firm or rubbery texture
Itching or tenderness
Pain or sensitivity to touch
Restricted movement (if located over joints or mobile skin areas)

Keloid scars, in particular, may feel hard or lumpy and can cause psychological distress due to their size and location, especially on visible areas like the chest, shoulders, neck, or earlobes.

Causes of Hypertrophic and Keloid Scars

Both hypertrophic and keloid scars result from overactive fibroblasts, the cells responsible for producing collagen during wound healing. When this process is dysfunctional, it leads to excessive collagen deposition, particularly type III collagen (seen in scar tissue).

Common triggers include:

Surgical incisions (e.g C-sections, orthopaedic surgery, thyroid surgery, breast surgery)
Acne or folliculitis
Burns
Trauma or cuts

Body piercings or tattoos
Vaccination sites
Insect bites

Risk Factors for Hypertrophic and Keloid Scars

Certain factors can increase your likelihood of developing abnormal scars:

Genetics – A personal or family history of keloids significantly raises the risk.
Darker skin tones – Individuals with Fitzpatrick skin types IV–VI are more prone to keloid formation.
Age – Most common between the ages of 10 and 30.

Wound tension or infection – Increases the chance of hypertrophic response.
Location of injury – Areas like the chest, shoulders, jawline, and upper back are more susceptible.

Treatments for Hypertrophic and Keloid Scars – Overview

Treatment can be challenging, especially for keloids, and often requires a multimodal approach. The goal is to reduce scar size, soften texture, reduce symptoms, and prevent recurrence.

Treatment options include:

Topical therapies

Laser treatments

Injectable therapies (steroids, polynucleotides)

Surgical revision

Combination therapies for improved outcomes

Topical Creams for Hypertrophic and Keloid Scars

Best for: Early-stage or post-surgical scars

Topical treatments (scar gel) may soften and flatten scars when used consistently over several months. They are most effective during the remodelling phase (up to 12 months after injury).

Key ingredients:

Silicone gel or sheets: Proven to reduce scar height and discolouration by hydrating and protecting the scar.
Vitamin E: Reduces inflammation and provides an antioxidant effect

Limitations:

Ineffective for large, mature, or nodular keloids.
Troublesome, requires consistent application (1–2 times daily for several months).

Fractional CO₂ Laser for Hypertrophic and Keloid Scars

Best for: Hypertrophic and smaller keloid scars

Fractional CO₂ lasers work by delivering focused thermal energy to the skin, removing abnormal scar tissue and creating microscopic injuries that stimulate collagen remodelling and promote smoother skin.

Benefits:

Reduces scar thickness and rigidity.
Improves skin texture and pigmentation.
Increases absorption of topical or injectable treatments.

Treatment plan:

5-6 sessions spaced 4–6 weeks apart.
May be combined with steroid or Rejuran injections for enhanced results.

Downtime:

Temporary redness and swelling are common.
Must be used cautiously in darker skin tones to avoid post-inflammatory hyperpigmentation.

Fractional CO2 laser treatment for keloid scar

Steroid Injections for Hypertrophic and Keloid Scars

Best for: Thick, painful, or itchy scars

Intralesional corticosteroid injections (e.g., triamcinolone acetonide) are considered the first-line treatment for both hypertrophic and keloid scars.

Mechanism:

Suppresses collagen synthesis.
Reduces inflammation and fibroblast activity.

Advantages:

Noticeable softening and flattening within weeks.
Reduces itching and discomfort.

Protocol:

Steroid injections given every 4-6 weeks till a good response (typically requires 4-6 treatments)

Risks:

Skin thinning (skin atrophy), loss of pigmentation (hypopigmentation) and development of small blood vessels (telangiectasia)

Rejuran Polynucleotide Injections for Hypertrophic and Keloid Scars

Best for: Hypertrophic and keloid scars

Rejuran Healer, derived from salmon DNA-based polynucleotides, is a regenerative injectable that promotes cell repair and collagen remodelling.

Mechanism:

Stimulates fibroblast activity in a controlled and regenerative manner.
Reduces inflammation
Improves tissue hydration, elasticity, and structure.

Benefits:

It may help normalise collagen formation in early hypertrophic scars.
Promising adjunctive treatment to laser resurfacing, steroid injections and scar revision surgery.

Protocol:

Injected directly into or around the scar.
Typically 3–4 sessions, spaced 4-6 weeks apart.

Clinical evidence: While still emerging, early studies and case reports suggest Rejuran may reduce inflammation and improve scar appearance, especially when combined with laser or steroid therapy.

Surgery for Hypertrophic and Keloid Scars

Best for: Large, symptomatic and recurrent scars

Surgical removal may be considered for bulky or painful scars, but must be approached with caution—keloids have a high recurrence rate after excision.

Surgical options:

Scar excision and primary closure: Removal of scar with layered wound closure.
Scar excision with Z-plasty or W-plasty

Risks:

Recurrence of keloid scars

Best practice:

Combine with steroid injections or silicone scar gel immediately after scar revision surgery.

Scar revision surgery with Z or W plasty

Conclusion

Hypertrophic and keloid scars represent a complex healing disorder, influenced by genetics, trauma, and immune responses. While they can be challenging to manage, a wide range of medical and aesthetic treatments are available to improve both their appearance and symptoms.

For mild or early-stage scars, topical silicone therapy may be sufficient. In more severe or resistant cases, fractional laser therapy, steroid or polynucleotide injections, and scar revision surgery can deliver excellent results, especially when used in combination.

As with all scar treatments, early intervention, professional evaluation, and personalised treatment planning are key to success. If you’re struggling with abnormal scars, consult an experienced doctor to determine the best approach for your skin and scar type.