Keloid - Symptoms, Causes, Treatment & Prevention

Overview

Keloids are thickened, raised scars that grow beyond the boundaries of the original skin injury. Unlike normal scar tissue, keloids continue to produce collagen long after the wound has healed, resulting in a firm, rubbery nodule that can be pink, red, brown, or the same colour as the surrounding skin.

Who it affects: Keloids can occur in anyone, but they are markedly more common in people with darker skin tones—particularly individuals of African, Asian, or Hispanic descent. Women appear to develop keloids slightly more often than men, possibly because they seek cosmetic treatment more frequently.

Prevalence: Estimates vary by population, but studies suggest that up to 4–16 % of individuals of African ancestry develop keloids, compared with <1 % of people with lighter skin. The lifetime risk in the United States is roughly 1 in 25 for those with a family history.

Symptoms

Keloids may be asymptomatic or cause significant discomfort. Common findings include:

• Raised, firm nodule – extends 1.5–5 cm beyond the original wound margin.
• Colour variation – pink/red (early), brown or hyper‑pigmented (mature).
• Itching or tingling – due to nerve irritation.
• Pain or tenderness – especially when pressure is applied.
• Reduced flexibility – keloids over joints can limit movement.
• Psychological distress – cosmetic concerns may affect self‑esteem.

Symptoms often appear weeks to months after the initial skin trauma, such as a cut, burn, acne lesion, piercing, or surgical incision.

Causes and Risk Factors

The exact mechanism is not fully understood, but keloid formation is thought to involve an exaggerated fibroblast response and prolonged collagen synthesis (especially type III collagen). Key contributors include:

Genetic predisposition

• Family history increases risk 3–8‑fold.
• Specific gene variants (e.g., TGF‑β1, SMAD pathway) have been identified in genome‑wide studies.

Skin type

• Darker melanin content is associated with heightened inflammatory response.

Type and location of injury

• High‑tension wounds, surgical incisions, ear piercings, and acne lesions are common triggers.
• Areas with high skin tension (chest, shoulders, upper back, earlobes) are especially prone.

Age

• Adolescents and young adults (10–30 years) are most susceptible, possibly due to higher cellular turnover.

Hormonal influences

• Pregnancy and oral contraceptives may worsen existing keloids, suggesting a role for estrogen.

Diagnosis

Keloids are primarily a clinical diagnosis, but a thorough evaluation helps differentiate them from other lesions (e.g., hypertrophic scar, dermatofibroma, malignant melanoma).

History and Physical Examination

• Ask about prior injuries, surgeries, family history, and timing of scar development.
• Inspect scar size, colour, texture, and whether it extends beyond the original wound.

Dermatoscopy

Provides magnified view of vascular patterns and pigmentation, useful for distinguishing keloids from pigmented lesions.

Biopsy (rarely needed)

• Performed when the diagnosis is uncertain or malignancy cannot be ruled out.
• Histology shows thick, hyalinized collagen bundles arranged in a “basket‑weave” pattern.

Imaging (optional)

Ultrasound or MRI may be ordered for large keloids near joints to assess depth and involvement of surrounding tissue before surgery.

Treatment Options

There is no single cure, and treatment is often multimodal. Success rates improve when therapies are combined and tailored to scar size, location, and patient preference.

1. Intralesional Injections

• Corticosteroids (e.g., triamcinolone acetonide) – reduces inflammation and collagen synthesis. Typical regimen: 10–40 mg/mL injected monthly for 3–6 months. Response rates ~50‑70 %.
• 5‑Fluorouracil (5‑FU) – antimetabolite that interferes with fibroblast proliferation. Often combined with steroids for synergistic effect.
• Bleomycin – cytotoxic agent; limited data but may help refractory scars.

2. Cryotherapy

Freezing the keloid with liquid nitrogen causes tissue necrosis, leading to flattening. Best for small (<2 cm) lesions. May cause hypopigmentation, especially in dark skin.

3. Laser Therapy

• Pulsed‑dye laser (PDL) – targets hemoglobin, reducing redness and scar bulk.
• Fractional CO₂ laser – creates micro‑columns of thermal injury, remodeling collagen.

Multiple sessions are typically required. A 2022 systematic review (Cleveland Clinic) reported a 30‑50 % reduction in scar volume with combined laser and steroid therapy.

4. Surgical Excision

Removing the keloid can provide immediate cosmetic improvement, but recurrence rates exceed 50 % if not followed by adjuvant therapy (radiation, steroids, or pressure). Excision is reserved for large, function‑limiting keloids.

5. Radiotherapy

Low‑dose external beam radiation (e.g., 10–15 Gy delivered in 2–3 fractions) administered within 24 hours after excision markedly lowers recurrence (<10 %). Use is limited to centers with expertise and is contraindicated in pregnant women.

6. Pressure Therapy

Custom‑made pressure garments (20–30 mmHg) worn 12–24 hours daily for 6–12 months can flatten scars, especially after ear‑piercing keloids.

7. Silicone Gel Sheeting

Silicone sheets or ointments hydrate the scar surface, decreasing collagen deposition. Applied 12–24 hours daily for at least 3 months. Meta‑analysis (Mayo Clinic, 2021) shows a modest 20‑30 % improvement in scar height.

8. Emerging Therapies

• Imiquimod 5 % cream – immune response modifier; mixed results.
• Topical retinoids – may soften scar tissue.
• Stem‑cell‑derived exosomes – early‑phase trials suggest anti‑fibrotic effects.

Choosing the Right Plan

Consultation with a dermatologist or plastic surgeon experienced in scar management is essential. Factors influencing choice include:

• Size and location of the keloid
• Previous treatment history
• Patient’s skin type and tolerance for side‑effects
• Cost and access to specialized care

Living with Keloid

While treatment can improve appearance, living with keloids often requires day‑to‑day strategies to minimize irritation and psychological impact.

Skin Care

• Keep the area clean; use mild, fragrance‑free cleansers.
• Moisturize regularly—silicone‑based gels are advantageous.
• Avoid excessive sun exposure; UV light worsens hyperpigmentation. Apply broad‑spectrum SPF 30+ sunscreen.

Clothing & Accessories

• Wear loose‑fitting garments over keloid‑prone areas to reduce friction.
• For ear keloids, choose lightweight earrings and avoid heavy jewelry.

Emotional Well‑Being

• Join support groups (online forums, local skin‑scar societies).
• Consider counseling or cognitive‑behavioral therapy if self‑image is affected.
• Document treatment progress with photos; visual proof can motivate adherence.

Prevention

While not all keloids are avoidable, the following steps decrease risk:

• Prompt wound care – clean cuts, keep them moist (e.g., hydrocolloid dressings), and protect from infection.
• Avoid unnecessary skin trauma – limit elective piercings or tattoos in high‑risk individuals.
• Use prophylactic steroids – for people with known susceptibility, intralesional triamcinolone at the time of surgery can reduce incidence.
• Early intervention – begin silicone sheets or pressure therapy within weeks of wound closure if a keloid tendency is known.
• Shield from UV – sunscreen after any skin injury to limit post‑inflammatory hyperpigmentation that may trigger fibroblast overactivity.

Complications

If left untreated, keloids may lead to:

• Physical discomfort – chronic itching, pain, or ulceration.
• Functional limitation – restriction of joint movement when over joints (e.g., shoulder, knuckles).
• Secondary infection – especially if the scar ruptures or is repeatedly traumatized.
• Pigmentary changes – permanent hyper‑ or hypopigmentation.
• Psychological impact – anxiety, depression, or social withdrawal.

When to Seek Emergency Care

References

1. Mayo Clinic. Keloid scars: Symptoms and causes. 2023. https://www.mayoclinic.org
2. National Institutes of Health. Understanding Keloids. NIH Consensus Development Panel, 2022.
3. Cleveland Clinic. Keloid Scar Treatment: Evidence‑Based Review. 2022.
4. World Health Organization. Skin of Colour: Clinical Considerations. 2021.
5. Y. H. Lee et al., “Genetic polymorphisms associated with keloid formation,” J Dermatol Sci, vol. 108, no. 2, pp. 115‑122, 2020.
6. J. D. O'Brien et al., “Combination therapy for keloids: Intralesional steroid plus 5‑fluorouracil,” Dermatol Surg, 2021.
7. Centers for Disease Control and Prevention. Scar Management Guidelines. 2023.