Hypertrophic Burn Scar Research: From Quantitative Assessment to Designing Clinical Sequential Multiple Assignment Randomized Trials

This article explores the current options for the quantitative assessment of hypertrophic burn scars. It also introduces a novel type of randomized, controlled trial, which relies on heterogeneity of the subject population to improve the predictive value of personalized treatment strategies.

Reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour

BACKGROUND

Bruising is one of the most common types of injury clinicians observe among victims of violence and other trauma patients. However, research has shown commonly used qualitative description of cutaneous bruise colour via the naked eye is subjective and unreliable. No published work has formally evaluated the reliability of tristimulus colourimetry as an alternative for assessing bruise colour, despite its clinical and research applications in accurately assessing skin colour. The purpose of this study was to systematically evaluate the test-retest and inter-observer reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour.

METHODS

Two researchers obtained repeated tristimulus colourimetry measures of cutaneous bruises with participants of diverse skin colour. Measures were obtained using the Minolta CR-400 Chomameter. Commission Internationale d'Eclairage (CIE) L*a*b* colour space was used. Data was analysed using intraclass correlation coefficients (ICC), Cronbach's alpha, and minimal detectable change (MDC) on all three L*a*b* values.

RESULTS

The colorimeter demonstrated excellent test-retest or intra-rater reliability (L* ICC=0.999; a* ICC=0.973; b* ICC=0.892) and inter-rater reliability (L* ICC=0.997; a* ICC=0.976; b* ICC=0.982).

CONCLUSIONS

With consistent placement, the tristimulus colourimetry is reliable for the objective assessment and documentation of cutaneous bruise colour for purposes of clinical practice and research. Recommendations for use in practice/research are provided.

A systematic review of objective burn scar measurements

BACKGROUND

Problematic scarring remains a challenging aspect to address in the treatment of burns and can significantly affect the quality of life of the burn survivor. At present, there are few treatments available in the clinic to control adverse scarring, but experimental pharmacological anti-scarring strategies are now beginning to emerge. Their comparative success must be based on objective measurements of scarring, yet currently the clinical assessment of scars is not carried out systematically and is mostly based on subjective review of patients. However, several techniques and devices are being introduced that allow objective analysis of the burn scar. The aim of this article is to evaluate various objective measurement tools currently available and recommend a useful panel that is suitable for use in clinical trials of anti-scarring therapies.

METHODS

A systematic literature search was done using the Web of Science, PubMed and Cochrane databases. The identified devices were then classified and grouped according to the parameters they measured. The tools were then compared and assessed in terms of inter- and intra-rater reproducibility, ease of use and cost.

RESULTS

After duplicates were removed, 5062 articles were obtained in the search. After further screening, 157 articles which utilised objective burn scar measurement systems or tools were obtained. The scar measurement devices can be broadly classified into those measuring colour, metric variables, texture, biomechanical properties and pathophysiological disturbances.

CONCLUSIONS

Objective scar measurement tools allow the accurate and reproducible evaluation of scars, which is important for both clinical and scientific use. However, studies to evaluate their relative performance and merits of these tools are scarce, and there remain factors, such as itch and pain, which cannot be measured objectively. On reviewing the available evidence, a panel of devices for objective scar measurement is recommended consisting of the 3D cameras (Eykona/Lifeviz/Vectra H1) for surface area and volume, DSM II colorimeter for colour, Dermascan high-frequency ultrasound for scar thickness and Cutometer for skin elasticity and pliability.

Longitudinal burn scar quantification

Quantitative studies of the clinical recovery of burn scars are currently lacking. Previous reports validate the objective, precise, diagnostic capabilities of high-frequency ultrasound to measure thickness, the Cutometer(®) to measure pliability and the Mexameter(®) to measure erythema and pigmentation of scars. Thus, we prospectively quantified clinical characteristics of patient-matched, after burn hypertrophic scar (HSc), donor site scar (D) and normal skin (N) using these instruments. One investigator measured 3 sites (HSc, D, N) in 46 burn survivors at 3, 6, and 12 months after-burn. A mixed model regression analysis, adjusting p-values for multiplicity of testing, was used to compare means among sites and time points. Participants were 41.2±13.5 years old, 87% males, predominantly Caucasian, with an average of 19.5% body surface area burned. HSc thickness decreased significantly between 3 and 6, 6 and 12, and 3 and 12 months (all p<0.0001), but remained thicker than D and N skin (all p<0.0001). Pliability differed significantly between HSc, D and N sites at all time points (all p<0.0001), with HSc and D increasing between 3 and 12 months (p<0.05) but not reaching normal. HSc and D sites were significantly more erythematous than normal skin (p<0.05) at 3 and 6 months but D sites approached normal by 12 months. The only time points at which pigmentation significantly differed were the HSc and D sites at 6 months. Thickness, pliability, erythema and pigmentation of N skin remained similar over the 12 months. We found that post-burn HSc thickness, pliability and erythema differed significantly from D and N skin at 3, 6, and 12 months and does not return to normal by 12 months after-injury; however, significant improvements towards normal can be expected. Donor sites are redder than normal skin at 3 and 6 months but can be expected to return to normal by 12 months. Although the color of HSc and D sites change markedly with time these color changes are primarily due to changes in redness of the site, not melanin in this primarily Caucasian population.