Re-recognition of the role of roughness in keloid assessment

Under visual observation, keloids are more rough than normal skin. This roughness may be used to assess the activity and severity of keloids but lacks the support of objective and accurate evidence. The purpose of this study was to verify the role of roughness in the development of keloids and to clarify the advantage of roughness in the comprehensive assessment of keloids. Patients with keloids who attended Peking Union Medical College Hospital were recruited. Keloids were classified into progressive, stable, and atrophic stages based on the change in size over the past year and blood perfusion. The keloids were evaluated using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). The roughnesses of the keloid and normal skin were measured using the Phaseshift Rapid In vivo Measurement Of the Skin (PRIMOS), and blood perfusion was measured using laser speckle contrast imaging (LSCI). Thirty-three patients with a total of 81 keloids were included. The surface roughness values Sa, Sq, and Sz of the keloid region were 243.70 (143.85–328.05), 316.20 (179.85–475.20), and 1708.20 (1098.30–4087.20), respectively, which were 4.87, 4.80, and 3.08 times higher than those of normal skin. There were significant differences in roughness among the different keloid stages. A significantly strong correlation between roughness and other assessed indices was found. Roughness as a morphological characteristic is of great value in the evaluation of keloids. It is recommended as an important examination for keloids.