Novel treatment approaches for keloids and hypertrophic scars in skin of colour

Dear Editor,

Keloids and hypertrophic scars are excessive fibrous tissue proliferations resulting from abnormal wound healing. ¹ Surgical removal and intralesional corticosteroids are mainstay treatments, but in skin of colour (SOC), these often lead to recurrences and dyspigmentation. ¹ Keloids disproportionately affect Black, Asian, Hispanic and Middle Eastern populations, ² attributed to genetic factors affecting collagen synthesis and melanocyte activity. ³ , ⁴

We conducted a systematic literature search in Embase and Ovid MEDLINE up to 4 October 2024, following PRISMA guidelines (PROSPERO: CRD42024606309). Search terms included “keloid”, “hypertrophic scar”, combined with treatment modalities and SOC descriptors (Figure S1—https://doi.org/10.5281/zenodo.16891689). Extracted data included study design, sample size, demographics, scar aetiology, treatments, outcomes, follow‐up durations and adverse events (Table S1—https://doi.org/10.5281/zenodo.16891689). We assessed quality using the Oxford Centre for Evidence‐Based Medicine 2011 Levels of Evidence.

After screening 778 articles, 37 studies with 2004 patients and keloids were included. Ethnic distribution was 32% Black, 39% Asian, 9% Caucasian and the remainder Hispanic, Indian/Middle Eastern or others. African, African American and Black were used interchangeably in the literature. Similarly Asian was used in the source literature, but represents numerous ethnicities. Recognizing these limitations, for this review, we have consolidated ethnic backgrounds to Black, Asian, Hispanic and Caucasian.

The most common scar aetiologies included ear piercing, surgery, trauma, acne and burns. Surgical monotherapy comprised 29% (293/1000) of treated keloids, with excision alone yielding 68% complete resolution (CR) yet 32% recurrence. Black (92 patients) and Asian (87 keloids) cohorts showed moderate‐to‐high CR but also demonstrated a moderately high recurrence rate. Intralesional cryosurgery (23% of surgical monotherapy) often resulted in partial resolution and significant hypopigmentation in Fitzpatrick III–VI.

Non‐surgical monotherapies represented 46% (458/1000) of treatments, mostly involving radiation. Brachytherapy attained a 73% CR among Fitzpatrick III–VI but was associated with infection, dermatitis and hyper−/hypopigmentation (over 120 total reported events). Soft x‐ray therapy reached a 50% CR, with Black participants sometimes exhibiting long‐term pigment changes. Intralesional corticosteroids (38% of medical monotherapies) offered up to a 50% CR in Black patients but risked hypopigmentation and atrophy. Bleomycin provided a 100% partial resolution, defined as any improvement in size and scarring, in Asian participants but induced hyperpigmentation in 71%. Oral tofacitinib showed partial responses. The CR rate of Asian and Hispanic participants in intralesional corticosteroids, bleomycin and tofacitinib was minimal.

Combination approaches (50%, 1004/2004) improved results across most ethnicities. Surgical excision plus radiation was common (65%, 651/1004) and yielded 88% CR, with higher success in Asian (372) and Black (125) patients. However, recurrent dyspigmentation remained a concern. Other regimens—excision plus corticosteroids, verapamil or cryotherapy—also demonstrated elevated CR (55%–66%) while reducing recurrence rates compared to monotherapies. Tension offloading devices reported 92% CR in an Asian cohort, underscoring potential utility for high‐tension areas in SOC.

Personalized strategies hinge on balancing efficacy with pigment preservation. ⁵ Black patients may benefit from limited radiation exposure to minimize discolouration; Asian patients might tolerate cryotherapy or bleomycin. Although treatments such as 5‐Fluorouracil, imiquimod, and interferon have been explored in the management of keloid scars, the literature did not provide sufficient data on skin colour. Another limitation is the heterogeneity in outcome reporting, with some studies providing patient‐level data and others reporting per keloid while some reported scales and others reported as subjective ‘improved’. SOC‐focused protocols, incorporating culturally sensitive counselling and robust follow‐up, are paramount for optimizing keloid outcomes while respecting patients' concerns about scar appearance and potential dyspigmentation. The findings are also limited by sample sizes and a predominance of retrospective and uncontrolled studies. There is a need for high‐quality, controlled studies focusing on SOC populations to develop optimized, culturally sensitive treatment protocols.

FUNDING INFORMATION

This research received no specific grant from any funding agency in the public, commercial or not‐for‐profit sectors.

CONFLICT OF INTEREST STATEMENT

CS: Has received honoraria from AbbVie, Leo, Pfizer, Miravo, Novartis, UCB and Sanofi/Regeneron unrelated to this work. ADL, SJ, RK, KARY, MP, RSQG and RB: No conflicts of interest to declare.

ETHICAL APPROVAL

Not applicable.

ETHICS STATEMENT

Not applicable.

DATA AVAILABILITY STATEMENT

The data underlying this article are available in the article and in its online supplementary material.