Just a few minutes in the shower, bath, or pool is enough to turn your fingers and toes into wrinkly prunes. While most people see it as a harmless quirk of the body, doctors say skin wrinkling—known as aquagenic wrinkling—may also offer surprising clues about chronic illnesses.
Why Skin Wrinkles in Water
Wrinkling usually appears within three to four minutes of soaking in warm water, particularly at temperatures above 40°C (104°F). That’s because the skin on our fingers and toes is thicker than elsewhere on the body, containing more dead skin cells rich in keratin. These cells soak up water, swell, and create folds in the skin.
At the same time, the autonomic nervous system constricts blood vessels beneath the skin, reducing blood flow and causing the tissue to shrink. Scientists believe this wrinkling evolved as a survival trait, improving grip on wet objects like rocks or slippery surfaces.
On its own, the effect is harmless. But researchers say the degree of wrinkling—or lack of it—can sometimes signal underlying health problems.
What Wrinkling Says About Disease
- Diabetes: People with diabetes often show less wrinkling after a bath. This is because diabetes can damage nerves in the fingers and toes (peripheral neuropathy), reducing sweat gland and blood vessel function. With less water absorption, the skin doesn’t wrinkle as much.
- Parkinson’s Disease: Patients with Parkinson’s, especially those with hemiparkinsonism (affecting one side of the body), may also wrinkle less. The disease kills nerve cells that produce dopamine, which also help control blood vessels and sweat glands. In some cases, one hand may wrinkle normally while the other barely does.
- Cystic Fibrosis: In contrast, people with cystic fibrosis (a genetic disorder affecting about 40,000 Americans) often develop excessive wrinkling, especially on the palms. Studies show up to 80% of cystic fibrosis patients experience increased aquagenic wrinkling, likely due to imbalances in their sweat glands. Because of this strong link, doctors recommend screening if unusual or severe wrinkling is noticed.
A Small Sign With Big Meaning
For most people, prune-like fingers after a swim are nothing to worry about. But dermatologists and neurologists agree that unusual wrinkling—or a lack of it—may provide important early warning signs of chronic conditions such as diabetes, Parkinson’s, or cystic fibrosis.
So next time you step out of the shower, those wrinkles on your fingers may be telling you more than you think.
