A vesicle, or blister, is a thin-walled sac filled with a fluid, usually clear and small. Vesicle is an important term used to describe the appearance of many rashes that typically consist of or begin with tiny-to-small fluid-filled blisters.
Review Date 4/14/2015
Updated by: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.