Herpes simplex virus type 1 (HSV-1) can cause groups of small blisters that usually appear on the lip and around or inside the mouth. The groups of blisters are commonly called cold sores. They may be itchy or painful.
Current as of: February 26, 2020
Author: Healthwise Staff Medical Review: Sarah A. Marshall, MD - Family Medicine Adam Husney, MD - Family Medicine Martin J. Gabica, MD - Family Medicine Kevin C. Kiley, MD - Obstetrics and Gynecology