Keloids and Hypertrophic Scars: Prevention and Treatment

Overview / Definition Keloids and hypertrophic scars are types of abnormal scars that arise from an exaggerated healing response following skin injury. While both involve excessive collagen deposition, keloids extend beyond the borders of the original wound and do not regress over time, whereas hypertrophic scars remain confined to the wound area and may improve with time. Epidemiology Keloids are more prevalent in individuals with darker skin and can occur in approximately 10-15% of patients following skin trauma. Hypertrophic scars are also common but are less likely to form in individuals with lighter skin tones. Highest incidence in African descent Common in young adults and adolescents More frequent following surgical procedures, burns, or acne Pathophysiology / Mechanism The pathogenesis of keloids and hypertrophic scars is complex and multifactorial. Both conditions involve an imbalance in collagen synthesis and degradation. Key factors include: Fibroblast proliferation and increased collagen production Altered extracellular matrix remodeling Immunological factors and inflammation Genetic predisposition Clinical Presentation Keloids typically present as raised, thickened areas of scar tissue that can be itchy, painful, or tender. They may vary in color from pink to dark brown. Hypertrophic scars, while also raised, are usually red or purple and may flatten over time. Key features include: Keloids: Extend beyond the original injury site, persist indefinitely Hypertrophic scars: Confined to the original injury site, may improve within 6 months to 2 years Diagnosis / Workup The diagnosis of keloids and hypertrophic scars is primarily clinical. A thorough history and physical examination are essential. Additional workup may be warranted in atypical cases: Review of patient history (e.g., prior surgeries, skin conditions) Physical examination to assess scar characteristics Consider biopsy in atypical cases to rule out other conditions (e.g., dermatofibroma, sarcom