are canker sores caused by a virus
More often, canker sores are caused by a tissue injury in the mouth or stress. Another canker sore cause is foods with a high citrus content such as oranges and tomatoes. Medical issues such as Celiac disease, Crohnâs disease, or an impaired immune system may also trigger canker sores to appear.Oral herpes is caused by a virus that is spread through body fluids.anker sores are caused by damage to the mouth, foods or an underlying disease, while oral herpes sores are caused by a virus. Eventually, cold sores will become crusted while canker sores will simply go away.