Saidala 24: Keloid scars

Definition

Keloid scars are benign fibroproliferative growths that extend beyond the original wound margins and do not regress spontaneously. They result from excessive collagen deposition during the wound healing process and can be symptomatic, causing pain, itching, or restricted movement.

Epidemiology

More common in individuals with darker skin tones (African, Asian, Hispanic descent).
Peak incidence between ages 10 and 30.
Slight female predominance, partly due to higher rates of elective skin piercing and surgery.

Etiology and Pathophysiology

Triggered by skin injury such as surgery, burns, lacerations, acne, piercings, or vaccination sites.
Excessive fibroblast activity leads to overproduction of type III and type I collagen, resulting in thickened scar tissue that extends beyond the wound boundaries.
Genetic predisposition: familial cases linked to certain HLA subtypes.

Risk Factors

Darker skin pigmentation.
Positive family history.
Wounds under high tension (e.g., sternum, shoulders, upper back).
Delayed wound healing or infection.
Young age.

Clinical Features

Firm, raised, shiny nodules or plaques.
Pink, red, purple, or hyperpigmented depending on skin type and age of scar.
Extend beyond the original wound margins.
Symptoms: itching (pruritus), tenderness, burning sensation, sometimes pain.

Diagnosis

Clinical evaluation is usually sufficient.
No special tests required unless to differentiate from hypertrophic scars (which remain within wound borders).
Biopsy only if diagnosis is uncertain or malignancy suspected (rare).

Management

Treatment is challenging, and recurrence rates are high. A multimodal approach is often most effective.

1. First-Line and Non-invasive Treatments

A. Intralesional Corticosteroid Injections

Triamcinolone acetonide 10–40 mg/mL, injected into the lesion every 4–6 weeks.
Reduces inflammation, fibroblast proliferation, and collagen synthesis.
Side effects: skin atrophy, hypopigmentation, telangiectasia.

B. Silicone Gel Sheeting or Silicone Gel

Continuous application (12–24 hours daily) for several months.
Softens and flattens scars, improves color and symptoms.

C. Pressure Therapy

Pressure garments or dressings delivering 20–30 mmHg for up to 12–24 months.
Common in burn scar management.

2. Other Pharmacological and Local Therapies

A. 5-Fluorouracil (5-FU)

50 mg/mL intralesional injection, often combined with triamcinolone.
Inhibits fibroblast proliferation.

B. Verapamil

2.5 mg/mL intralesional injections; reduces extracellular matrix production.

C. Imiquimod 5% Cream

Applied nightly for several weeks after surgical excision to reduce recurrence.

D. Cryotherapy

Liquid nitrogen application to small keloids; causes tissue destruction and flattening.
Risk: hypopigmentation, blistering.

3. Procedural Treatments

A. Laser Therapy

Pulsed dye laser (PDL) 585–595 nm reduces redness, pruritus, and scar height.
May be combined with steroids or 5-FU injections.

B. Surgical Excision

Often combined with adjuvant therapies (steroids, radiation, imiquimod) to prevent recurrence.
Alone, excision has a high recurrence rate (45–100%).

C. Radiation Therapy

Low-dose radiation after excision (within 24 hours) reduces recurrence.
Used selectively due to potential carcinogenic risk.

Treatment Dosing Summary (Common Agents)

Triamcinolone acetonide: 10–40 mg/mL intralesional every 4–6 weeks.
5-Fluorouracil: 50 mg/mL intralesional weekly or combined with steroids.
Verapamil: 2.5 mg/mL intralesional every 3–4 weeks.
Imiquimod 5% cream: Apply nightly for 6–8 weeks post-excision.

Prognosis

Benign but often persistent.
High recurrence rates after treatment; combination therapy is most effective.
May improve with time but rarely resolve completely without intervention.

Prevention

Avoid unnecessary skin trauma in high-risk individuals.
Use silicone sheeting or pressure dressings early after surgery in high-risk sites.
Prompt treatment of any wound infection to promote proper healing.

Saidala 24

الصفحات

Tuesday, August 12, 2025

Keloid scars