Why Do Cold Sores Cause Skin Blisters?

A cold sore often begins with tingling, burning, or tenderness. Small blisters then appear, commonly around the lips, as the skin reacts to viral activity. The clear fluid is part of the skin’s inflammatory response; it is not pus by itself. Blisters can join together, break, form a crust, and gradually heal. Fluid from an active sore can spread the virus to another person or to another area of your own body, especially the eyes.

Keep the area clean and avoid picking, squeezing, or peeling the crust. Wash your hands after touching your mouth, and avoid kissing or sharing lip products, cups, towels, or razors while the sore is active. A cool compress may ease burning. A clinician or pharmacist can advise whether an antiviral treatment is suitable, particularly if treatment is started when tingling first appears.

Arrange medical advice if sores are unusually extensive, repeatedly return, do not begin settling, or make eating and drinking difficult. Seek urgent care for eye pain, eye redness, light sensitivity, or a sore near the eye, because herpes infection can harm the eye. People with weakened immunity should obtain prompt advice for a new or worsening outbreak.

Could this be a cold sore or another blistering condition? Would an antiviral help this episode? How can I reduce spread to household members and protect my eyes?