Ask Pippa

Why Does Soaking in Water Cause your Skin to Wrinkle?

Want to look old fast? Try soaking in the bathtub for an hour or two. The longer you soak, the more you'll look like the Creature from the Black Lagoon.

After a good soak, the skin on your fingers and toes gets really wrinkly. Why? It all has to do with how your skin is made up.

Skin is made of several layers. Each layer does something different. The top layer is called the epidermis. Just below that is a layer called the dermis. There is another layer underneath that.

As far as wrinkles go, the most important layer is the epidermis (the top layer, remember?). The very, very top part of the epidermis (nearest the surface of your skin) is called the horny layer.

This layer of skin happens to be quite good at soaking up water. Fingers and toes have a much thicker horny layer than other parts of the body -- about 40 times as thick.

After you've been soaking for a while, the horny layer has time to absorb a bunch of water and becomes puffy.

But the layers below the horny layer don't soak up water. This difference between the layers ends up forcing the horny layer to buckle or wrinkle.

Other parts of the body don't get as wrinkled after soaking simply because the horny layer is thinner. And a thin of this type of skin doesn't absorb as much water as a thick layer.

* The word dermis is from the ancient Greek word "derma"; meaning "skin".

* The skin is the largest organ of the human body.


- ???-

People Links

Your Body and Health: Centers for Disease Control and Prevention (kids)

Neuroscience for Kids