Keloids and hypertrophic scars both have a serious impact on appearance and function, but the diagnosis of keloid scars is often overlooked, so some doctors treat keloid scars as hypertrophic scars for simple surgical excision, which results in easy recurrence after surgery and affects the outcome.
The main points of differentiation between keloid and hyperplastic scar: the former usually exceeds the boundary of the damaged area, which is called infiltrative growth, and the abnormal growth persists, with obvious local itching and pain; hyperplastic scar has thickening, but the scar tissue does not exceed the boundary of the original injury, usually after 6-8 months and into the scar maturity, the itching and pain is reduced, and there may be different degrees of local atrophy and softening; keloid is common in young people. Keloid scars are common in young people, mostly on the chest, back of shoulder, face and neck, and earlobes; hyperplastic keloid scars can occur at any age and in any area; keloid scars can be secondary to small skin lesions such as mosquito bites, boils, or even ear piercings, while hyperplastic keloid scars are most often caused by trauma. It has been found that some keloid patients have autosomal dominant inheritance.
Pathologically, both keloid and hyperplastic scars show excessive deposition of extracellular matrix with no significant increase in the absolute number of fibroblasts. Typically, the former collagen fibers are arranged in a polycentric vortex and clearly demarcated from the normal skin, whereas the proliferative keloid collagen fibers are neatly oriented, parallel to the long axis of the scar, and gradually disappear into the surrounding normal skin.
In terms of treatment, hyperplastic keloid scars are more effective with compression therapy, while keloid scars are more ineffective; the former are less likely to recur after surgical excision, while keloid scars have a very high recurrence rate.