Quantitative Measurement of Hypertrophic Scar: Intrarater Reliability, Sensitivity, and Specificity

Abstract

The comparison of scar evaluation over time requires measurement tools with acceptable intrarater reliability and the ability to discriminate skin characteristics of interest. The objective of this study was to evaluate the intrarater reliability and sensitivity and specificity of the Cutometer, the Mexameter, and the DermaScan C relative to the modified Vancouver Scar Scale (mVSS) in patient-matched normal skin, normal scar (donor sites), and hypertrophic scar (HSc). A single investigator evaluated four tissue types (severe HSc, less severe HSc, donor site, and normal skin) in 30 burn survivors with all four measurement tools. The intraclass correlation coefficient (ICC) for the Cutometer was acceptable (> or =0.75) for the maximum deformation measure for the donor site and normal skin (>0.78) but was below the acceptable range for the HSc sites and all other parameters. The ICC for the Mexameter erythema (>0.75) and melanin index (>0.89) and the DermaScan C total thickness measurement (>0.82) were acceptable for all sites. The ICC for the total of the height, pliability, and vascularity subscales of the mVSS was acceptable (0.81) for normal scar but below the acceptable range for the scar sites. The DermaScan C was clearly able to discriminate HSc from normal scar and normal skin based on the total thickness measure. The Cutometer was less discriminating but was still able to discriminate HSc from normal scar and normal skin. The Mexameter erythema index was not a good discriminator of HSc and normal scar. Receiver operating characteristic curves were generated to establish the best cutoff point for the DermaScan C total thickness and the Cutometer maximum deformation, which were 2.034 and 0.387 mm, respectively. This study showed that although the Cutometer, the DermaScan C, and the Mexameter have measurement properties that make them attractive substitutes for the mVSS, caution must be used when interpreting results since the Cutometer has a ceiling effect when measuring rigid tissue such as HSc and the Mexameter erythema index does not discriminate normal scar from HSc.

Measurement of change in the mechanical properties of burned skin to therapist intervention with a vacuum device

“…reported as low as 0.07-0.50 [2,3]. Therefore, it would be beneficial for burn care providers to have access to reliable and valid instruments that provide high quality data regarding change in burn scars due to interventions.…”

“…Vacuum device materials testing systems apply a negative pressure in a closed space and the amount of skin that is drawn in to the chamber is measured with reflected light. The use of a vacuum device has been demonstrated to reliably distinguish between normal skin, skin graft donor sites and hypertrophic scars following burns with acceptable inter-rater reliability [2,3].…”

Viscoelastic assessment of skin quality for clinical applications

“…While the parameters are relatively easily obtained, their biological and diagnostic relevance is still very much questionable, especially considering the large variability within control groups (Nedelec et al 2008a(Nedelec et al , 2008b.…”

A holistic exploration of paediatric partial thickness burn care in the outpatient setting

“…Dermascan C has been found to be a reliable in the measurement of burn scar thickness in adult burn scar populations [91,92]. The device is, however, clinically reported to have a lengthy and complex set-up process (for example, the precise application of film over the transducer head) and is cumbersome to transport and use, which may not be logistically appropriate for a pediatric population.…”

“…MHz echogenic ultrasound which uses a water-filled transducer to produce high resolution soft tissue images at a depth of 15mm [91,92]. Dermascan C has been found to be a reliable in the measurement of burn scar thickness in adult burn scar populations [91,92].…”