A dermatologist says: The most classic trigger is sun exposure, so it's important to protect your lips with balm. Since cold sores are caused by a strain of herpes virus, once you have one, you may want to try an anti-viral medication like valacyclovir or acyclovir. Stay well-hydrated and avoid acidic foods, and make sure not to kiss anyone or drink from the same glass while you're having an outbreak.—Jon Starr, M.D., adjunct
A dietitian says: Some studies show that lysine, an amino acid found in dairy products, poultry, eggs, and potatoes, may help prevent the recurrence of cold sores. Yogurt can be particularly beneficial, since it also contains natural bacteria that help strengthen the gut and boost immunity. Avoid spicy foods, which can aggravate the pain.—Pat Vasconcellos, R.D., nutritionist based in
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