Water immersion skin wrinkling is an indicator of limb
sympathetic function. Routine clinical usage of this enigmatic
phenomenon is hampered by poor endpoint quantification, which
involves counting skin folds. The recent discovery of the
importance of vasoconstriction in immersion wrinkling suggests
digital blood flow or volume changes as better endpoints. Water
probably initiates the wrinkling process by altering epidermal
electrolyte homeostasis as it diffuses into the porous skin of
the hands and soles via its many sweat ducts. Altered epidermal
electrolyte homeostasis would lead to a change in membrane
stability of the surrounding dense network of nerve fibers and
trigger increased vasomotor firing with subsequent
vasoconstriction. Vasoconstriction, through loss of volume,
leads to negative digit pulp pressure resulting in a downward
pull on the overlying skin, which wrinkles as it is distorted.
The degree of wrinkling would directly depend on the change in
digit tip volume and implies any process inducing loss of digit
volume will precipitate wrinkling. This review discusses the
physiology of water immersion wrinkling and explores its
potential as an indicator of limb sympathetic
dysfunction.