Keloid

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What this article covers

• Overview

  Fibroproliferative scar that outgrows the wound: a benign dermal growth of disorganized, excess collagen that extends beyond the borders of the original skin injury, forming firm, raised, shiny…

• Epidemiology

  Darker skin pigmentation: incidence is markedly increased in Fitzpatrick skin types IV-VI compared with lighter skin.

• Risk factors

  Darker skin pigmentation: the single strongest risk factor.

• Pathophysiology

  Excess TGF-beta drives fibroblast overactivity: aberrant TGF-beta signaling sustains fibroblast proliferation and collagen synthesis well beyond normal wound remodeling.

• Clinical features

  Firm, raised nodule or plaque extending beyond the wound: the hallmark finding is scar tissue that has grown past the borders of the original injury, often with clawlike projections; this extension is what clinically defines a keloid.

• Differential diagnosis

  Hypertrophic scar: stays confined within the original wound margin, arises earlier (within weeks of injury), and commonly regresses over months, versus a keloid, which extends beyond the wound, can…

• Diagnosis

  Clinical diagnosis based on morphology and history: keloid is diagnosed clinically; the defining criterion is fibrotic tissue extending beyond the margins of the original wound, with a history of…

• Management

  First line, intralesional triamcinolone acetonide 10-40 mg/mL: Small or thin papules: 5-10 mg/mL.

• Complications

  Recurrence after treatment: common even with combined excision plus adjuvant therapy; excision alone carries a particularly high recurrence rate, often exceeding 50%.

• Prognosis

  Rarely regresses without treatment: an untreated keloid continues to grow slowly over years rather than flattening spontaneously.

• Prevention

  Avoid elective procedures at high-risk sites in a known keloid-forming patient: counsel against ear piercing, elective cosmetic surgery, and tattooing at the earlobe, shoulder, presternal chest, and jawline.