2 days ago
New TEWL to Predict Diabetic Foot Ulcer Recurrence
A new study proposes a subtle but potentially game-changing shift in how clinicians define wound healing in diabetes: not by what the eye sees, but by what the skin silently leaks.
The study, led by Chandan K. Sen, PhD, MS, director of the McGowan Institute for Regenerative Medicine of the University of Pittsburgh, introduces a noninvasive tool that measures transepidermal water loss (TEWL) to assess whether a diabetic foot ulcer (DFU) has truly healed or if it remains vulnerable beneath the surface.
The innovation lies in recognizing what Sen refers to as 'invisible wounds' — ulcers that appear closed based on the US Food and Drug Administration's definition (intact skin and no drainage for 2 weeks) but still suffer from impaired skin barrier function. That dysfunction, the study shows, can be measured with a handheld device that quantifies water vapor escaping from the skin.
Seeing Beyond the Surface
In the study, published in Diabetes Care , researchers used a simple, point-of-care evaporimeter to measure water loss from DFU sites that had achieved visual closure. Wounds with elevated TEWL values — meaning greater skin permeability — were significantly more likely to reopen than those with water loss similar to the surrounding healthy skin.
The implications are substantial. Whereas current standards rely almost entirely on visual inspection, this physiologic marker offers an objective, reproducible measure of skin barrier recovery. In essence, TEWL could help distinguish between 'cosmetically healed' wounds and those that are functionally sound.
A Problem Hidden in Plain Sight
Roughly 31% of people with DFUs will eventually face amputation — and nearly half of those who do won't survive beyond 5 years. A major contributor to this grim trajectory is ulcer recurrence, often occurring at the same site and shortly after supposed closure.
These findings echo previous calls in the literature to reframe wound healing as the beginning of remission rather than resolution. In fact, based on the best available data from our unit and others, DFU recurrence is so common that it may be better conceptualized as a chronic condition with episodic flares — akin to cancer or heart failure — rather than an isolated event.
TEWL as a Biomarker for Remission
The TEWL approach supports a more nuanced understanding of wound healing — one that emphasizes barrier restoration, not just epidermal reepithelialization. Sen and his team suggest that TEWL be integrated as a complementary endpoint in both clinical care and regulatory definitions of healing.
In practical terms, the use of a TEWL measurement could help clinicians determine which patients may benefit from continued offloading, advanced wound care dressings, or antimicrobial protection, even after a wound appears to be healed.
Toward a More Durable Closure
As diabetic foot care increasingly shifts toward long-term management and prevention, the ability to identify wounds at risk for reulceration becomes essential. The TEWL metric fits seamlessly into that framework, offering a noninvasive, cost-effective, and scalable solution.
This aligns with broader trends in the field, including recent work that highlights the importance of postclosure surveillance, monitoring, and biomechanical offloading to maintain remission.
Conclusion
Presented with compelling clinical and physiological rationale, this new TEWL-based method could redefine what it means for a wound to be truly healed. Rather than signaling the end of care, visual closure might soon be seen as the beginning of a carefully monitored remission — guided, in part, by the invisible signal of water loss through the skin.
If validated across larger populations and settings, TEWL could become a staple in diabetic foot protocols, marking a small but vital evolution in our effort to reduce preventable amputations.
