Objective assessment of burn scar vascularity, erythema, pliability, thickness, and planimetry

There is currently a lack of objective methods to assess scars.

The objectives of this study were to (1) determine the pattern of scar formation up to 24 months after a burn, compare clinical and photographic scar assessment, and determine what percentage of scars became hypertrophic after a major trauma and (2) replace each clinical parameter of a clinical scar scale by objective measurements.

Scars from 62 patients were evaluated from the acute phase up to 24 months after the burn, using photographs and clinical assessment during visits. Photographic planimetry helped estimate the percentage of scars that became hypertrophic. Thereafter, 69 patients had scars evaluated using clinical assessment and several instruments to evaluate pigmentation, erythema, pliability, thickness, and perfusion. The sensitivity and specificity of each instrument were determined regarding their ability to correlate with the parameters of hypertrophic and nonhypertrophic scars. Analysis of variance and Tukey's test were used in statistical analysis, with p<.05 indicating significance.

Increased scar hypertrophy occurred between 6 and 12 months after the burn, and less than 30% of scars were hypertrophic at 18 to 24 months. Objective assessment of pliability and erythema, but not pigmentation, correlated significantly with clinical evaluation of hypertrophy. Hypertrophic scars had significantly higher perfusion than nonhypertrophic scars. A new scar rating system is proposed, based on the sensitivity and specificity of each instrument, to correlate with hypertrophic and nonhypertrophic scars.

Objective rating systems using reliable instruments can be used to replace subjective scar assessment. Larger multicenter prospective studies should test this new scale in scars due to other mechanisms of injury.