What are the causes of cold sores and what can be done for it?

Laser: Canker sores or aphatous ulcers have no know cause except they are triggered by trauma, stress, spicy, citrus food. Not everyone gets them though. They are recurring and even though there are some medication that help cut the cycle down from 14 days, I am a big proponent of laser treatment . Recent studies have shown laser treatment of the area can stop the pain immediately and cut the cycle

Contact with virus: Causes would be from contact with an infected person with the herpetic virus. If you have a small cut abrasion or break in your skin this allows transfer of the virus. You may or not see any cold sores on the infected person. Asking about a history of cold sores or HIV infection before getting familiar with someone is prudent.