“What causes white sores in your mouth?”

Core sores on the lip are small blisters that are caused by Herpes Simplex Virus. They commonly clear up within 7 – 10 days but could last from 1 to 3 weeks. Cold sores are the most contagious when rupture, although they are contagious from the firt time you feel it oround your mouth. There are antiviral drugs that help to get rid of them. Those drugs could be acyclovir, valacyclovir, penciclovir as well as others. If you are having frequent outbreaks, consider going to your healthcare provider for a prescribed medication. Core sores are triggered by different things which includes sunlight, trauma (in your case the needle injection could be the etiologic factor), and women in their menstrual period. The cold sire spread through saliva or close contact which is often by kissing or shearing utensils, straws, lips balm and towels. Thank you.