Snapshot A 26-year-old Chinese woman presents to her dermatologist for a persistent growth on her chest. She had previously burned a small portion of her pre-sternal skin while curling her hair 2 years ago. While the burn healed without any problem, she noticed a protuberance where the burn previously was. She reports that this growth seems to be larger than the original burn. On physical exam, she has a 5 cm elliptical firm, pink, and shiny growth. While counselling that this may not go away completely, her dermatologist agrees to start intralesional steroid injections. (Hypertrophic scars) Introduction Clinical definition abnormal and excessive scarring in response to dermal injury, resulting in hypertrophic scars or keloids Epidemiology incidence keloid login to view 1 more bullet demographics most commonly in ages 10-30 risk factors keloid login to view 4 more bullets hypertrophic scar login to view 2 more bullets both login to view 2 more bullets Etiology keloid previous trauma spontaneous hypertrophic scar previous trauma Pathogenesis dysregulation of wound healing recall normal wound healing stages are login to view 1 more bullet keloid ↑↑ type I and type III collagen login to view 2 more bullets hypertrophic scar ↑ type III collagen login to view 2 more bullets Prognosis keloid recurrence is frequent will not regress over time hypertrophic scar recurrence is rare may regress over time Presentation Symptoms abnormal scarring occurs after trauma or injury often itchy or painful (keloids > hypertrophic scar) keloid may take months to years to develop hypertrophic scar usually appears within 1 month Physical exam scarring along previous site of wound well-defined, firm, and shiny pink, purple, or hyperpigmented irregular borders Studies Biopsy indications only if clinical diagnosis is uncertain Histology keloid thick collagen fibers with abundant mucoid matrix disorganized type I and III collagen hypertrophic scar thin collagen fibers with minimal mucoid matrix myofibroblasts parallel type III collagen Differential Basal cell carcinoma Treatment Medical intralesional corticosteroid injections indication login to view 1 more bullet silicone sheeting indication login to view 1 more bullet Operative surgical excision indication login to view 1 more bullet Complications Contractures limiting mobility associated with hypertrophic scars