Differentiating scar behaviour: Transepidermal water loss in delayed healing and skin graft scars

The relationship between transepidermal water loss (TEWL), scar parameters (such as elasticity and colour), and time has not been comprehensively explored. This study aimed to elucidate the association between scar activity and TEWL in burn scars resulting from delayed healing and skin grafting, while also investigating temporal trends. Forty skin-grafted scars and forty delayed-healing scars were assessed for TEWL, colour, and elasticity using a combination of objective and subjective measurement tools. Matched uninjured skin areas were included as controls. The results revealed that delayed-healing scars exhibit significantly higher TEWL than skin-grafted scars, both of which demonstrate elevated TEWL compared to normal skin. TEWL levels in skin-grafted scars normalized at approximately 9.1 months post-injury, whereas delayed-healing scars required nearly 15 months to normalize. Increased TEWL was positively correlated with higher POSAS-O scores, vascularity, erythema, and elasticity measurements. Comparison of two TEWL measurement devices showed strong similarities overall, but notable variations at the extremes of the measurement range existed. This study uniquely quantifies and elucidates the relationship between TEWL and scar parameters in the two distinct types of burn scars. The results highlight the positive correlation between TEWL and both subjective and objective measures of scar activity, suggesting TEWL as an indicator of scar progression. These findings position TEWL as an essential metric in scar management, offering valuable guidance for the effective use of silicone gel sheets and moisturizers to regulate and optimize scar progression.