Uncle Jack is one of our clinic's most familiar faces. In his 60s, he’s been living with diabetes for over two decades. He shows up for checkups with a smile, takes his medication, follows the no-sugar rule as best he can, and keeps active. Life isn’t glamorous, but it’s stable.
That’s why, when a small blister on the sole of his foot spiraled into a serious ulcer last winter, it came as a shock. He hadn’t even noticed it—nerve damage from years of diabetes had dulled his sense of pain. Within days, the blister turned into a deep wound that landed him in the hospital.
Thankfully, after a few weeks of treatment, the wound closed. The skin had sealed over, and it looked, at least from the outside, like everything was back to normal. His doctor cautioned him: “The skin on the bottom of your feet is more fragile than it looks.” But in Jack’s mind, things were fine again. If it’s closed, it’s healed—right?
Not exactly.
A few months later, the same spot cracked open again—worse than before. What he thought was healing had only been the beginning of a recurring nightmare.
When "Healed" Isn't Really Healed
Uncle Jack's story is more common than you might think. Among people with diabetes, foot ulcers are one of the most frequent—and dangerous—complications. And as a new study funded by the U.S. National Institutes of Health (NIH) shows, many wounds that look healed on the surface may still be vulnerable underneath.
Researchers discovered that a deceptively simple measurement—trans-epidermal water loss (TEWL)—can be used to determine whether a wound is truly closed, or just appears to be. TEWL tells us how much water is evaporating from the skin, which turns out to be a critical indicator of whether the skin’s protective barrier has been fully restored.
Because here’s the hard truth: the biggest danger often comes after a wound closes.
A Forgotten Signal: Water Loss Through the Skin
The NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) launched a study to explore TEWL and its potential in wound care. At first glance, it might sound overly technical—measuring how much water your skin is “leaking” doesn’t sound like it has much to do with healing.
But it does. And here's why.
Your skin is a waterproof shield. It holds moisture in, and keeps bacteria and viruses out. When that barrier is compromised—say, by an ulcer—it loses its protective abilities. Even if the wound looks fine on the surface, the inner structure might still be fragile and leaky.
TEWL is like checking whether your roof really got sealed after it was patched. It might look fine in the sunlight, but without a proper waterproof layer, the next storm will expose every weakness.
The Numbers That Matter
In the study, researchers followed more than 400 diabetic patients who had foot ulcers that were visually healed. Using specialized equipment, they measured the TEWL values at the previously injured sites and monitored participants for 16 weeks.
Here’s what they found:
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Among those with high TEWL (more water escaping from the skin), 35% experienced a wound reopening.
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For those with low TEWL, the recurrence rate was just 17%.
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Patients with high TEWL were 2.7 times more likely to have a recurrence than those with low TEWL.
These numbers aren’t just statistics—they’re a wake-up call. They tell us that the appearance of healing isn’t enough. A wound that seems fine to the naked eye may still be on the verge of reopening.
Real-Life Lessons: It's the Invisible That Hurts the Most
Have you ever had a blister that dried up and scabbed over, only to tear open again the first time you wore stiff shoes? For people with diabetes, that’s not just inconvenient—it can be dangerous.
Due to nerve damage (diabetic neuropathy), patients often don’t feel small injuries. A reopened ulcer might not cause pain, but it can quickly become infected, or even lead to amputation if untreated.
After his wound reopened, Uncle Jack admitted, “I didn’t even feel it. I just noticed my sock was a little damp. That’s when I knew something was wrong.”
It’s not enough to wait for a scab to form. What’s beneath the surface matters more than what we can see. And TEWL offers doctors a new tool to help identify when the skin is truly strong enough to handle normal wear and tear again.
Healing Is More Than Skin Deep
One of the biggest takeaways from this research is that we need to rethink what "healing" really means.
For years, doctors have relied on visual assessments—if the skin looks closed and dry, it must be healed. But this new data shows that TEWL can be a much more accurate predictor. In the future, doctors may use it as part of routine post-treatment evaluations for diabetic foot wounds.
Imagine this: before discharging a patient, a doctor checks the TEWL value of the healing site. If the reading is high, they delay discharge, recommend more rest, or schedule closer follow-up care. That simple step could prevent infections, amputations, and even save lives.
Because the stakes are high. Studies show that once a diabetic patient undergoes a lower-limb amputation, the 5-year mortality rate can be as high as 50%. This isn’t just about avoiding pain or inconvenience. It’s about survival.
From Reaction to Prevention
What this study really highlights is a shift in how we approach chronic wound care. We’re moving from a mindset of "treat when it happens" to "predict and prevent before it does."
TEWL monitoring is like an early-warning system. It helps us spot weak points before they collapse. Instead of waiting for the wound to open again, we can reinforce the skin’s defenses proactively.
It’s a reminder that true healing is functional, not just visual. The skin must be ready to protect again—not just look pretty.
Practical Advice for Patients and Families
If you or a loved one is managing diabetes, especially with a history of foot ulcers, here are some tips inspired by this research:
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Don’t trust your eyes alone: Just because a wound looks closed doesn’t mean it’s fully healed. Follow your doctor’s recommendations closely and continue foot care even after wounds disappear.
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Ask about TEWL testing: More clinics are starting to adopt this non-invasive, painless test. If you’re unsure whether your wound has truly healed, ask your provider whether TEWL assessment is available.
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Keep the skin hydrated: Dry skin is more prone to cracks. Moisturize regularly—but avoid over-moisturizing, which can cause dampness and infection.
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Watch for subtle signs: If you notice discoloration, swelling, or even dampness in socks, take it seriously. Numbness doesn’t mean nothing’s wrong.
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Make foot care part of the daily routine: Check your feet every day. Even if you can’t feel pain, your eyes can still catch early warning signs.
The Quiet Power of Science
This NIH-funded research may seem technical on the surface, but its implications are deeply human. It’s about giving clinicians and patients better tools, so people like Uncle Jack don’t have to face the same wound again and again.
Science can't walk for you, dress your wounds, or feel the pinch of a shoe. But it can shine a light into the places we can’t see—and sometimes, that light is enough to change the outcome.
Real healing isn’t just what we see. It’s what we trust won’t break again.