What should you know about red light for cold sores?

Cold sores are grouped blisters that commonly occur on or around the lips. They can tingle, burn, crust, and become sore as they heal. A red light device may be promoted to support comfort or healing, but home devices differ and the light does not remove the virus from the body.

Touching the area, sharing lip products, kissing, or oral contact can spread the infection while the sore is active. A lamp can also irritate an open blister if it creates heat or if the skin is handled repeatedly.

Keep the area clean and avoid picking the blister or peeling the crust. Wash your hands after touching your lips, do not share towels or cosmetics, and follow any device eye-protection and distance instructions. Stop light exposure if it causes heat, burning, swelling, or worsening pain.

Early assessment can help decide whether [Antiviral Treatment](/treatments/medical-dermatology/antiviral-therapy/) is appropriate, particularly when outbreaks are frequent, severe, or beginning. If you are unsure whether a blister is a cold sore, arrange a [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/). See more about [Skin Blisters](/symptoms/skin-blisters/).

Seek prompt medical advice if the sore is near the eye, you develop eye pain or light sensitivity, the outbreak is widespread, you cannot drink comfortably, or you have a weakened immune system. Get urgent help for severe eye symptoms or trouble swallowing. A sore that does not heal or keeps returning also needs assessment.

Does this look like a cold sore or another blistering condition? Would antiviral treatment help if started now? How can I reduce spread to household members? Is a red light device suitable while the skin is open?