Keloid and hypertrophic scar

Hypertrophic scars	Keloid scars
Common in all races and ages.	Less common; more frequent in Fitzpatrick skin types III to VI. Self-reported in 16% of Black individuals. More likely in Chinese than Indian or Malaysian origin. Least affected: White-skinned individuals and albinos. Genetic association with certain HLA haplotypes and blood group A. Associated conditions include Rubinstein-Taybi syndrome, Dubowitz syndrome, Noonan syndrome, and others.
Causes Occur with high tension on healing wounds.	Causes Develop after minor injuries or spontaneously. Common triggers: Trauma, burns, insect bites, surgery, cryotherapy, acne, infections, and immunization.
Clinical Features Pink to red, slightly raised or flat. Uncomfortable and itchy. Occur within weeks of injury. Confined to the wound area. Common locations: Shoulders, chest, earlobes, upper arms, cheeks.	Clinical Features Purplish-red, firm, smooth, raised. Uncomfortable and itchy. Grow beyond the wound area. Can occur years after injury.
Treatment Likely to resolve spontaneously, respond better to treatment.	Treatment Likely to persist, resistant to treatment.

Complications

• Cosmetic disfigurement.
• Adverse social and psychological effects.
• Thick, tight keloids may limit movement and limb growth in children.
• Suppuration.

Diagnosis

• Clinical diagnosis based on history and features.
• Skin biopsy if diagnostic uncertainty.
• Histology: Increased fibroblasts and collagen in hypertrophic scars; keloidal collagen in keloids.

Differential Diagnoses

• Skin tumors (e.g., adnexal tumor, Spitz naevi, dermatofibromas, dermatofibrosarcoma).
• Cutaneous squamous cell carcinoma.
• Cutaneous pseudolymphoma.
• Lobomycosis.
• Morphoea (localized scleroderma).

Treatment for Keloids and Hypertrophic Scars

General Principles

• Hypertrophic scars often resolve spontaneously and respond better to treatment.
• Keloids are persistent and more resistant to treatment.
• The primary aim is to reduce cosmetic disfigurement, functional problems, pain, and itch.

Treatment Modalities

1. Corticosteroids
   • Intralesional steroids are the first-line treatment.
     • Multiple injections at 4-6 week intervals.
     • Dose: 10-40 mg/cc of triamcinolone.
     • Can be used alone or with other modalities.
   • Topical ointments and steroid-impregnated tapes reduce itching and burning.
2. Cryotherapy
   • Delivery methods: spray, contact, or intralesional-needle cryoprobe.
   • Multiple treatments required.
   • Freeze-thaw cycles: 10-20 seconds.
   • Less desirable for darker skin types due to post-treatment pigmentary changes.
3. Surgical Excision
   • High recurrence rate (45%-100%). may result in a larger scar if not combined with additional therapies.
   • Should always be paired with adjuvant therapy:
     • Post-surgical radiation.
     • Intralesional steroid injections.
4. Radiotherapy
   • Best used as adjuvant therapy 24-28 hours post-excision.
   • Use caution in patients under 18 and in areas like head, neck, and breast due to carcinogenesis risk.
5. Laser Therapy
   • Successive sessions with 585 nm pulse-dye laser and 1065 nm ndYAG laser.
   • Induces flattening and regression of keloids.
6. Other Treatments
   • Topical imiquimod post-excision.
   • Intralesional botox.
   • Cryotherapy
     • Application of extreme cold to the scar.
     • Causes controlled tissue destruction and reduces scar size.
   • Intralesional 5-fluorouracil
     • Chemotherapeutic agent injected into the scar.
     • Helps to reduce fibroblast activity and scar formation.
   • Pressure Dressings and Garments
     • Used to apply consistent pressure to the scar.
     • Helps to flatten and soften the scar tissue.
     • Typically worn for several months.
   • Silicone gel sheeting/patches – Worn for 12–24 hours per day for at least 8 to 12 weeks.These patches help flatten and soften the scar over time.

Adjuvant Therapy

• Radiotherapy: Used in refractory cases to prevent recurrence after excision.
• Interferon: Injection of interferon to reduce keloid size.
• Verapamil: Calcium channel blocker injected into the scar to reduce fibroblast activity.

Combination Therapies

• Combining different treatment modalities often yields better results.
• Example: Surgical excision followed by corticosteroid injections or radiotherapy to prevent recurrence.

Follow-Up and Maintenance

• Regular follow-up to monitor scar progression and response to treatment.
• Long-term maintenance therapy may be necessary for persistent keloids.

Prevention

• Strategies post-trauma:
  • Minimal tension surgery.
  • Eversion of wound edges during suturing.
  • Limit the number of sutures.
  • Avoid unnecessary surgery/cosmetic procedures in keloid-prone individuals and areas.

Outcome

• Hypertrophic and keloid scars are harmless and do not change into skin cancer.
• Patients may experience cosmetic and functional impacts.