A vesicle is a small fluid-filled blister.
A vesicle is small -- it may be as tiny as the top of a pin or up to 5 or 10 millimeters wide.
In many cases, vesicles break easily and release their fluid onto the skin. When this fluid dries, yellow crusts may remain on the skin surface.
Many diseases and conditions can cause vesicles. Common examples include:
It is best to have your health care provider examine any skin rashes, including vesicles.
Over-the-counter treatments are available for certain conditions that cause vesicles, including poison ivy and cold sores.
When to contact a medical professional
Call your doctor if you have any unexplained blisters on your skin.
What to Expect at Your Office Visit
Your doctor will look at your skin. Some vesicules can be diagnosed simply by how they look.
In many cases, however, additional tests are needed. The fluid inside a blister may be sent to a lab for closer examination. In particularly difficult cases, a skin biopsy may be needed to make or confirm a diagnosis.
High WA, Tomasini CF, Argenziano G, Zalaudek I. Basic principles of dermatology. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. Dermatology. 3rd ed. Philadelphia, Pa.: Elsevier Saunders; 2012:chap 1.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.