Oh dear, I have done it again! I have been in the bath longer than I intended. The smell of lavender oil and the warm water relaxed me so much that I almost dozed off and it made my fingers and toes go all wrinkled and shrivelled like prunes. Itís all to do with osmosis, the movement of water from an area where it is abundant to another area where it is in short supply.
Our skin is amazing in protecting us from many nasty germs, dirt and other unwanted things that might cause damage to our body. It is the first line of defence keeping things at bay. At the same time, it holds all our body fluids in. It is fairly waterproof so that we do not blow up like a balloon when we are caught out in the rain or have a shower or bath! However, it is not completely waterproof.
Skin is quite complex, made up of many different layers with big Latin names like epidermis, dermis, Malpighian layer, etc. But hey, you donít need to worry about all these. To understand the wrinkling of your fingers, we just need to worry about the top or outer layer of the skin known as the epidermis. In fact, the exposed part of our skin is made up of dead dried and flattened tiny little cells. We shed these dead cells constantly as the skin rubs against clothes and other things coming into contact with it. Hereís one of those useless bits of information - you may have noticed that if we do not dust or wipe surfaces of the furniture in the house, it gets covered in dust. A majority of this dust is our dead skin cells that we have shed and have settled on top of our chest of drawers or tops of shelves, or even your tights if you wear them Ė yeakh!!
Right, going back to our pruned fingers and toes, we make our hands and feet work harder than any other parts of our skin. For this reason, the skin is thickest on hands and feet for their protection. The epidermis cells (known as keratinocytes) are linked together with an intracellular protein skeleton known as keratin, which as it happens, is water loving. The bottom part of the epidermis divides quite rapidly and, in turn, push the cells lying above, higher upwards. As they are pushed upwards, due to lack of space, they become flattened. These cells have an inbuilt programmed death after a number of divisions and so the top layer consists of the dead and dried up cells. When we soak in the bath for some time, these cells start absorbing the water and will swell up. However, the inside of the fingers and toes do not swell. This leaves a larger surface area on the top and it has to go somewhere! It becomes bunched up, a bit like a concertinaed paper or like a gathered skirt, or as buckled railway line that expands on a hot day. The skin gets pulled up into ridges and troughs, giving the prune-like effect. You donít notice this effect much on the rest of the body where the skin is much thinner. Our nails and hair also contain keratin that will also absorb some water, which is why the nails become softer as they are soaked in the water. It is thought that there may be an evolutionary reason for the prune fingers and toes in that it may help you grip better when hands and feet are wet!
But, donít worry, this wrinkled effect is not permanent and is reversible as the water evaporates when you dry yourself. Although, initially, it hydrates your skin, it leaves it drier as the water evaporates off and the warm water and soap/detergents wash off your natural oils in your skin. You can reduce this dryness by adding oil to your bath water or applying some hydrating lotion to your skin after your bath. So, next time you decide to luxuriate in a warm fragrant bath, add a little oil to reduce this prune effect!!