What is the appropriate diagnosis and treatment approach for a patient with a suspected keloid, particularly in individuals with darker skin types?

Keloid Differential Diagnosis

Primary Differential Diagnoses

Keloids must be distinguished from hypertrophic scars, dermatofibromas, dermatofibrosarcoma protuberans, and other fibroproliferative lesions through clinical history and examination findings. 1

Key Distinguishing Features of Keloid

• Growth pattern: Keloids extend beyond the original boundaries of injury or trauma, while hypertrophic scars remain confined to the wound site 1
• Temporal behavior: Keloids continue to grow over time and do not spontaneously regress, unlike hypertrophic scars which may stabilize or improve 1, 2
• Clinical presentation: Nodular lesions with pain, pruritus, erythema, and induration are characteristic 2
• Patient demographics: Higher occurrence in individuals with dark, pigmented, ethnic skin, particularly those of African, Asian, and Hispanic descent 1
• Family history: Strong familial heritability and ethnic predisposition 1

Differential Diagnoses to Consider

Hypertrophic scar is the most common differential:

• Remains within original wound boundaries 1
• May regress spontaneously over months to years
• Less likely to have progressive growth

Dermatofibroma:

• Typically smaller, firm dermal nodule
• Does not arise from trauma or surgical sites
• "Dimple sign" positive (dimples inward with lateral compression)

Dermatofibrosarcoma protuberans:

• Rare malignant tumor requiring tissue biopsy for definitive diagnosis 2
• Progressive growth but typically lacks keloid's characteristic symptoms
• Requires histopathological confirmation

Scar tissue from cryotherapy or other treatments:

• May develop keloid formation as a complication, particularly in darker-skinned individuals 3
• History of prior treatment is key distinguishing factor

Diagnostic Approach

Diagnosis is primarily clinical, based on medical history of preceding trauma or surgery combined with characteristic physical findings. 2

Essential History Elements

• Preceding injury: Any trauma, surgery, piercing, acne, or inflammatory process 1, 2
• Timeline: Progressive growth over months to years following initial injury 1
• Symptoms: Pain, itching, and inflammation are common 1
• Ethnic background: African, Asian, or Hispanic descent increases likelihood 1
• Family history: Strong heritability pattern 1
• Quality of life impact: Psychosocial burden and functional impairment 1

Physical Examination Findings

• Location: Most common on earlobes, shoulders, chest, and upper back
• Appearance: Raised, firm, nodular lesions extending beyond original wound 1
• Color: Often darker than surrounding skin, may be erythematous 2
• Texture: Smooth, shiny surface with firm consistency 2
• Growth: Progressive enlargement beyond initial injury site 1

Confirmatory Testing When Needed

Tissue biopsy should be performed when:

• Clinical diagnosis is uncertain 2
• Concern for dermatofibrosarcoma protuberans or other malignancy exists 2
• Lesion has atypical features or rapid growth

Ultrasound examination can be used as an adjunct diagnostic tool to assess lesion depth and characteristics 2

Critical Pitfalls to Avoid

• Failing to distinguish from hypertrophic scar: This leads to inappropriate treatment expectations, as hypertrophic scars may improve spontaneously while keloids require active intervention 1
• Overlooking ethnic predisposition: Darker-skinned patients have significantly higher risk and may develop keloids from minor trauma 1
• Inadequate assessment of psychosocial impact: Keloids cause considerable quality of life reduction requiring comprehensive evaluation 1
• Treating without considering recurrence risk: Keloids have high recurrence rates (33% at 1 year, 50% at 5 years), necessitating prevention strategies 4
• Using aggressive treatments in high-risk patients: Cryotherapy and surgical excision can themselves cause keloid formation in predisposed individuals 3, 5