Objective Assessment Techniques: Physiological Parameters in Scar Assessment

Abstract

In order to assess new and often costly treatments, the need for objective scar measurement tools has become increasingly important. A combination of subjective and objective measures should be the aim of every researcher. Quantitative assessment of scars requires devices to measure their physical and physiological properties. Physiological scar parameters are scar characteristics relevant to pathological scarring which cannot be seen with the bare eye. This also means that they can only be assessed with objective assessment tools.Skin hydration is defined as the water content of the epidermis and the dermis, and the ability of the skin to retain water is important to avoid dry appearance of the skin and prolonged inflammation in scarring. Many approaches exist to measure skin water content. One single method is often not enough to capture all the relevant information. Trans-epidermal water loss, stratum corneum water content, and dermal water content are equally important and related to each other.Scar maturation has been related to transcutaneous oxygen tension, and it is hypothesized that low levels of transcutaneous oxygen pressure in evolving scars result from low oxygen diffusibility through scar tissue.Tactile sensitivity of the skin can be measured by esthesiometers. The Semmes-Weinstein monofilament test is found to be a feasible and reliable outcome measure to evaluate touch perception threshold in older upper extremities burn scars.

Clinical efficacy of silk sericin dressing with collagen for split-thickness skin graft donor site treatment

“…However, the evaluation by the device might specify the more apparent difference between the treatments. Besides, some parameters, especially physiological parameters representing the recovery of skin functions, seem difficult to evaluate by subjective methods due to minor differences or invisibility [167]. Therefore, the devices should be used to facilitate the evaluation of these parameters.…”

“…However, the functions of other appendages and their ability to produce natural moisture factors (NMF) cannot be evaluated from only TEWL. Therefore, the results of TEWL should be considered together with the results from directly measuring water content [167].…”

“…Skin hydration is the water content in the epidermis and dermis, indicating the recovery of water holding capacity. It was found that scars had lower hydration after complete healing for several months, leading to skin dryness and hypertrophic scar development [167]. Hydration of skin affects skin appearances such as smoothness and softness and influences skin function such as flexibility and desquamation [168,169].…”

“…Due to it being an open chamber, it should be used in the closed room controlling for temperature and humidity. Several studies used Tewameter to determine the epidermis's recovery function [59,188], and it has excellent inter-and intra-reliability, 0.96 and 0.95, respectively [167].…”

“…However, it should be done under very strict conditions with standardized test protocol to avoid the influence of environmental factors. Moreover, skin hydration is recommended to be reported as the differences or percentage change to reduce the influencing factors [167]. The results from Corneometer ® should be considered together with other physiological parameters such as TEWL [167,189].…”