Why your fingertips wrinkle when wet
Most of us know that if we sit for long enough in a bath, our fingers and toes wrinkle. Why does this happen?
An early idea stemmed from the fact that the skin on the surface of your fingers and toes is different from the skin covering the rest of your body. It’s thicker due to constant contact, abrasion, and pressure. Your fingertips and toetips contain networks of dense, tough connective tissue. This tough tissue anchors the outer skin to the underlying layers known as the dermis. It was thought that, if you soak in water long enough, water can leak into the outer skin, causing it to swell, while the more heavily anchored skin below stays drier and unswollen. The result – those temporary wrinkles on your fingers and toes.
But, in the 1930s, doctors noticed that patients with nerve damage didn’t get wrinkly in water. They began to think that skin that wrinkles when wet is linked to the nervous system. As the video above explains:
Bottom line: Skin wrinkling when wet is an active response of the nervous system to prolonged moisture.