Maturation of the human scar: An observational study

Background: The natural history of scar maturation in humans has never been formally described from either a clinical or a histologic standpoint. Methods: The maturation of incisional scars was observed in 58 healthy male volunteers who each had 2 x 1-cm incisional wounds created on the inner aspect of both upper arms. The resulting scars were photographed digitally at monthly intervals for 12 months and excised for histologic analysis at specific time points. All histologic specimens were stained using Masson's trichrome and reviewed together with the corresponding digital clinical scar images to produce macroscopic and microscopic descriptions of the maturation process. Results: Three distinct groups, each displaying a different rate of longitudinal progression of scar maturation, were identified from within the study group. The majority of volunteers belonged to a "representative" subset but distinct "poor" and "excellent" subsets were also identified. The poor subset invariably contained volunteers younger than 30 years of age, whereas the majority of the excellent subset comprised subjects older than 55 years of age. Conclusions: Scar maturation occurs as a series of defined macroscopic and microscopic stages over the course of 1 year. The rate of scar maturation varied within the study group, with older subjects (>55 years) displaying accelerated maturation, whereas a prolonged high turnover state and a retarded rate of maturation were observed in younger subjects (<30 years).