II. Definitions

  1. Keloid
    1. Derived from Greek "cheloides" or crab's claw
    2. Firm, Rubbery Nodules that proliferate in the first year of Skin Injury

III. Epidemiology

  1. More common in black, asian or hispanic patients (Keloids)
    1. Confers >15 fold increased risk
  2. Familial predisposition
    1. One third of Keloid patients have a first degree family member with Keloids
  3. Most common onset age 10 to 30 years old

IV. Pathophysiology

  1. Excessive fibrous repair response to Skin Injury
  2. Overgrowth of scar tissue at sites of Trauma (acne, Burn Injury, surgery, Ear Piercing, Tattoo or Skin Infection)
    1. Extension of lesion beyond Skin Injury site
    2. Onset 3 to 12 months after wound and tend to worsen overtime, maintaining depth>4 mm
    3. Contrast with Hypertrophic Scar which is immediate, localized to the wound, superficial and regresses over time

V. Risk Factors

  1. Dark skin as noted above
  2. Delayed healing (longer than 3 weeks)
  3. Burn Injury
  4. Severe acne
  5. Ear Piercing
  6. Varicella Vaccination

VI. Symptoms

  1. May be asymptomatic
  2. Pruritus
  3. Pain or Hypersensitivity

VII. Signs: Keloids

  1. Characteristics
    1. Firm, smooth, shiny, Skin-Colored Papules, Nodules, Plaques at or near prior Skin Injury
    2. Start as red or pink and become hyperpigmented later
  2. Distribution: Regions of high dermal tension
    1. Sternum or chest
    2. Lower Abdomen
    3. Upper arms
    4. Nape of neck or back
    5. Scalp
    6. Ear Pinna
    7. Cheeks and jaw line
    8. Major Joints

VIII. Differential Diagnosis

  1. Hypertrophic Scar
    1. Keloids, in contrast, grow beyond original injury margins and do not regress spontaneously with time
  2. Dermatofibroma
  3. Dermatofibrosarcoma Protuberans
  4. Desmoid tumor
  5. Scar Sarcoidosis
  6. Foreign Body Granuloma

IX. Course

  1. May continue to enlarge for years
    1. Contrast with Hypertrophic Scar which regresses over time

X. Management: First-Line therapy

  1. Intralesional Corticosteroid Injection
    1. Consider combining injection with Cryotherapy pretreatment below
    2. Adverse effects include local skin atrophy, dyspigmentation, Telangiectasias
    3. Triamcinolone Acetonide 10 mg/ml
      1. Dilute in 3 cc Lidocaine 1%
      2. Repeat injection monthly until improvement (typically 2-3 injections)
  2. Topical 5-Fluorouracil
    1. Adjunct to intralesional Corticosteroid Injection
    2. Apply weekly to biweekly for 6 to 8 weeks
    3. Khan (2014) J PAK Med Assoc 64(9): 1003-7 [PubMed]
    4. Jiang (2020) Aesthetic Plast Surg 44(5): 1859-68 [PubMed]
  3. Cryotherapy
    1. May be adjunct to Corticosteroid
    2. Lightly freeze hard Keloid before injection (may soften the lesion)
  4. Silicone Elastomer Sheeting (e.g. Kelo-cote, ScarAway)
    1. Applied to closed wound site for 12-24 hours over everyday for 2-3 months
    2. Use gels on the face and extensor surfaces (knees and elbows) and sheets on larger flat areas of closed skin

XI. Management: Refractory after one year

  1. Surgical Excision
    1. Not recommended as first-line therapy due to very high recurrence rate after excision (>50%)
    2. Combine surgical excision with adjunctive measures
      1. Corticosteroid Injection
        1. First injection at time of excision, then
        2. Reinject weekly for 3-5 weeks, then
        3. Reinject monthly for 3-6 months
      2. Consider also applying Silicone Elastomer Sheeting
      3. Consider applying Imiquimod 5% cream (Aldara) on alternate nights for 8 weeks after surgery
        1. More effective in low skin tension areas such as ear lobes
        2. Chuangsuwanich (2007) J Med Assoc Thai 90(7):1363-7 [PubMed]
  2. Other measures
    1. Pulsed dye laser
    2. Intralesional Verapamil (2.5 mg/ml) in combination with Silicone Elastomer Sheeting
    3. Intralesional Fluorouracil (50 mg/ml) injected 2-3 times weekly
    4. Intralesional Bleomycin (1.5 IU/ml, 0.1 ml) injected on up to 6 consecutive sessions
    5. Intralesional Interferon Alfa-2B 1.5 Million IU twice daily for 4 days
  3. References
    1. Atiyah (2007) Aesthetic Plast Surg 31(5): 468-92 [PubMed]

XII. Prevention

  1. Post-surgical prophylaxis
    1. Compression Bandage application
    2. Intralesional triamcinolone
    3. Postexcisional Imiquimod 5% cream (Aldara)
      1. Klotz (2020) Wound Repair Regen 28(1): 145-56 [PubMed]
    4. Radiotherapy
      1. Mankowski (2017) Ann Plast Surg 78(4): 403-11 [PubMed]
  2. Keep new wounds moist, clean and at rest
    1. Wash new wounds with soap and water, and irrigate under the water tap
    2. Apply non-antibiotic Emollient (e.g. petrolatum, Aquaphor)
    3. Apply cover bandage
    4. Avoid excessive movement and Stretching of the skin at new wound sites or following procedures
  3. Avoid topical irritants
    1. Neosporin (Contact Dermatitis risk)
    2. Vitamin E Capsules (local irritation, and no benefit for Wound Healing)
  4. Avoid Ear Piercings and other unnecessary procedures in those with Keloid or scar risk
  5. Wound closure techniques have similar scarring results (Dermabond vs Sutured closure)
  6. Silicone Elastomer Sheeting (e.g. Kelo-cote)
    1. Apply after Wound Healing (typically 3-4 weeks after onset)

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