aquagenic pruritus

[ăk′wə-jĕnĭk]
n.
  1. Intense itching that is the result of brief contact with water of any temperature but that does not produce visible changes in the skin, associated with local release of acetylcholine, mast-cell degranulation, and increased histamine concentrations.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.