There are various theories of why fingers and toes wrinkle in
water. Most biologists suggest that the tough outer layer of skin
made up of dead keratin cells is responsible. Keratin is a protein
found in hair, nails, and the outermost layer of our skin.
Our skin is made up of three layers:
- The subcutaneous tissue is the deepest layer. It contains
fats and connective tissue along with large blood vessels and
- The dermis is the middle layer. It contains the blood
vessels, nerves, hair roots, and sweat glands.
- The epidermis is
the topmost layer. It helps to prevent evaporation of water
from the body and to protect the internal
layers from harm.
The epidermis is made up of four layers:
- the stratum corneum
- granular layer
- squamous cell layer
- and basal cell layer
The stratum corneum is the outer layer of our skin - the part
that we can see and feel. This is the layer with the dead keratin
While a person is in the pool or a bathtub for a long time, the
dead keratin cells absorb water. This absorption causes the surface
area of the skin to swell, but the outer layer is tightly attached
to the living tissue. So, to compensate for the increased surface
area, our skin wrinkles.
So why does this happen to hands and feet and not to other parts
of the body? Because the hands and feet have the thickest layer
of dead keratin cells. Our hands and feet are subjected to a lot
of wear and tear. Imagine if the palm of our hands had skin as
thin as that on our backs. No fun playing basketball with skin
Scientists continue to look for the exact mechanisms of why our fingers and toes wrinkle when immersed in water (Wilder-Smith et al, Hsieh et al). One theory gaining recognition is the role of digital vasoconstriction (narrowing of blood vessels). When hands are immersed in water it seems that the nerve fibers are triggered to “shrink” and glomus bodies (body temperature regulators in the skin) in the hand lose volume, which then pulls the skin structures downwards to produce wrinkling. Studies on patients with loss of nerve function in their hands due to a disorder or replantation of amputated fingers exhibit no or slight wrinkling in the fingers when immersed in water (Hsieh et al). As the nerve functions return, so did the wrinkling.
For more fascinating facts about the skin see the following Web
sites and further reading sections.
the Skin - This Web site, from the British Association
of Dermatology, provides all types of information about
the skin, such as the importance of skin and
its role as a barrier, as well as information about
cancer and other diseases.
of the Skin - This Dermatology Health Guide, from
The University of Maryland Medicine, contains interesting
skin facts and information on skin diseases and conditions.
Whole Story on Skin - "Created by The Nemours Foundation's Center for Children's Health Media, Kids Health provides families with accurate, up-to-date, and jargon-free health information they can use." The section on skin provides interesting skin facts, an illustration of the epidermis, additional articles about the skin, and related web resources such as, Why does my skin get wrinkly in water?
World of Skin Care: an on-line reference by Dr. John
Gray, provided by the P&G Skin Care Research Center -
This reference from Procter and Gamble provides information
about the structure,
function, and care of skin as well as information about skin problems and aging.
The information is presented in a book format with a table of contents and index.
Faith Hickman. 101 questions about your skin that
got under your skin
until now. Brookfield,
CT, Millbrook Press, c1999. 176 p. (Juvenile).
- Bull, C and Henry, J.A. Finger wrinkling as a test of autonomic function. British medical journal, Feb. 26, 1977: 551- 552.
- Hseih, Ching-Hua et al. Paradoxical response to water immersion in replanted fingers. Clinical autonomic research, v. 16, June 2006: 223-227.
- Kareklas, Kyriacos, Daniel Nettle, and Tom V. Smulders. Water-induced finger wrinkles improve handling of wet objects. Biology Letters , v.9 (2), 2013.
Marc. The body's edge: our cultural obsession with
skin. New York, Henry Holt and Company, 1996. 242
Robbins, C.R. Skin in the Encyclopedia
of human biology. Edited by Renato Dulbecco.
v. 8. San Diego, Academic Press, c. 1997. p. 39-47.
Angela. Why do I get a sunburn? And other questions
about skin. Chicago, Heinemann Library, 2003. 32
- Wilder-Smith, Einar P.V. and Adeline Chow. Water immersion wrinkling is due to vasoconstriction. Muscle and nerve, v. 27, March 2003: 307-311.
more print resources...
Search on "skin," "skin--anatomy," or "dermatology--popular
in the Library of Congress Online
of human skin layers. From the National Institute of General Medical Sciences Web
The coastal defence guns: One of the crew takes a bath under the shadow of the gun. Prints and Photographs Catalog, Library of Congress.
Scale model of a bathtub made for Presindent Taft, who was nearly six feet tall and weighed 340 pounds. The original tub was 7 feet 1 inch long, 41 inches wide, and weighed one ton.
Cartoon originally from the National Weather Service. NOAA, Website.