A patch is a flat area of color change in the skin that is 1 cm or more wide.
Ball JW, Dains JE, Flynn JA, Solomon BS, Stewart RW. Skin, hair and nails. In: Ball JW, Dains JE, Flynn JA, Solomon BS, Stewart RW, eds. Seidel's Guide to Physical Examination. 8th ed. St Louis, MO: Elsevier Mosby; 2015:chap 8.
Reviewed By: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.