SCAR MATURATION IN THE AFRICAN CONTINENTAL ANCESTRY GROUP

Abstract

ABSTRACTThe University of ManchesterCatherine Lisa Jane TaylorA thesis submitted to the University of Manchester for the degree of Doctor of Medicine in the Faculty of Medical and Human Sciences.Scar maturation in the African Continental Ancestry Group.2012The natural history of scar maturation in humans has been described by Bond et al. (2008b) in a male European Continental Ancestry Group (ECAG). It is important that the natural history of scar maturation in humans is established for all skin types. This study therefore aims to describe clinically and histologically the maturation of scars in male volunteers from the African Continental Ancestry Group (ACAG).This study was performed as a single centre, methodology trial. Three incisions and a punch biopsy were carried out on each arm. Monthly assessments of the resultant scars included: investigator scar assessments; scar photography; VAS scoring by an Independent External Scar Assessment Panel; and objective measures of colour and scar mechanics. At various time points scars were excised for histology. Sixty male subjects of African Continental Ancestry between the ages of 18-56 years were recruited to take part in the study. The clinical appearance of a scar in the ACAG improves with time. Scar colour mismatch decreases and the mechanical properties of scars improve with time. Scar width increased over the 12 months. With the exception of scar contour and scar redness, a steady state was not achieved. Volunteer skin type was shown to influence the resulting scar appearance and not age. The histology of scar maturation in the ACAG over 12 months was described and scars classified into three groups each displaying a different rate of longitudinal progression of scar maturation. The process of collagen maturation is still ongoing at month 12; many scars demonstrated a prolonged high turnover state of collagen synthesis and degradation, rete ridge restoration and angiogenesis were still ongoing with persistent inflammation identified in scars up to Month 12. There is a strong correlation shown between the Clinical VAS scores and the Histology VAS scores for the papillary dermis which is of better quality than the reticular dermis. There is some evidence that young people (ACAG) and volunteers with darker skin have poorer scar histology. The spectrophotometry data indicated that the Fitzpatrick Skin Type Classification is a useful method of classifying the varying skin colours of this group of volunteers. In conclusion, scar maturation in the ACAG occurs as a series of defined macroscopic and microscopic stages over the course of 1 year. The process of scar maturation is not complete at 12 months. All scars showed evidence of improvement over the course of the study influenced in part by volunteer skin type and age. Results suggest that scar maturation in this study group occurs at a different rate and is of a different quality, compared to current knowledge of scar maturation in the ECAG.

Date of Award	31 Dec 2013
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Duncan Mcgrouther (Supervisor) & Mark Ferguson (Supervisor)