Since childhood, we’ve measured when it’s time to get out of the bathtub by our fingertips. When they start to look a bit like raisins, we know we’ve been in the water a little too long. But, why does this happen?
Our skin goes through something called keratinization. This is the process of moving old, flattened, “dead,” skin cells up to the surface of the epidermis in order to provide your skin with a water-proof barrier. Even with regular exfoliation, this waterproofing stays in tact. It’s the reason we can swim, soak, bathe, and sing in the rain without melting like the Wicked Witch of the West.
However, after soaking in the bathtub or swimming in the pool for long periods of time, our skin starts to lose salts. The salts normally keep our skin plump and hold water in. Without them, our skin starts to shrivel in response. Our extremities are the first to react to this salt loss, which is why we can look down and see raisin fingers and pruny toes.
Once your skin has been our of the water for enough time to regain its salt balance, the “pruniness” goes away. After all, your skin is one of your most resilient organs!