The skin-wrinkling test: principles and clinical applications.

Cutaneous wrinkling is a normal phenomenon that occurs on the palms in a reversible manner and results from vasoconstriction influenced by vasomotor function. It can be assessed through the skin-wrinkling test following water immersion, with the absence or reduction of wrinkling being associated with disorders affecting the dense network of sympathetic nerves in these regions. The literature suggests that this test may serve as a screening tool for small-fiber neuropathy, particularly in settings in which biopsy is not available. It is a rapid, inexpensive, and easily-accessible test. We herein review the principles of the skin-wrinkling test, its pathophysiology, and its clinical indications as a tool to evaluate the sympathetic component of the autonomic nervous system.