Bite-size answers to commonly asked questions from inquiring minds
Q. Why do your fingers and toes go wrinkly in the bath?
Did you know?
There are 45 miles of nerves in the skin of a human being.
The skin is the largest organ in our body and typically comprises 12-15% of out total
Source: Good Skin Health.
A. It can take some convincing to get my children into the bath but, once they are
in, it can be very difficult to get them out again. Recently, after another long
bathe, my five year old son asked me “Daddy, why do your fingers and toes go wrinkly
in the bath?” So what’s the answer?
Well, there are in fact various theories as to why our skin wrinkles when it’s submerged
in water. But many biologists currently think along the following lines...
Our skin is made up of an outer layer – called the epidermis – and an under layer
known as the dermis (it’s a little more complicated than that and there is also a
deeper third layer referred to as the subcutaneous tissue but that is out of the
scope of this answer). The epidermis is actually comprised of dead dry keratin cells
(keratin being a protein found in skin, nails and hair) which fall off us all the
time, some of which makes up the dust in our homes! Anyway, although we can’t really
see it on ourselves, it is covered with a special oily substance called sebum. This
oil helps to lubricate the skin and also makes it a little bit waterproof. However,
if we stay immersed in water for a length of time the sebum gets washed away and
our outer skin starts to absorb water more easily.
This absorption leads the skin to expand and increase in surface area. Because the
epidermis is attached or, if you like, ‘tied down’ to the dermis beneath, the only
way for it to deal with this increased surface area is to wrinkle. But why is it
only really noticeable in our fingers and toes?
Well, the skin on our hands and feet is actually thicker than around other parts
of our body in order to help protect us. This is because we touch many more things
with our fingers and toes and so the skin becomes thicker to help compensate. And
because it’s thicker (and some say not so ‘tied down’), it absorbs more water making
the wrinkling more conspicuous here.
So there we go! Now we know the answer to why do your fingers and toes go wrinkly