Prior to laser resurfacing your doctor will want to know if you have a history of cold sores. Any type of injury or insult to the skin can reactivate the herpes virus, which is responsible for cold sores. Laser resurfacing can definitely prompt a cold sore break out, and that is why we place patients with a history of cold sores on anti-viral medication prior to their procedure and a few days after. The medication will significantly minimize the risk of a cold sore break out.