A patch is a flat area of color change in the skin that measure 1 centimeter or more in diameter.
Call your health care provider if:
What to expect at your health care provider's office:
Review Date: 11/4/2012 Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.