Canker sores. Canker sores, known in medicine as aphthous stomatitis, are painful small ulcers on your tongue or gums. Unlike cold sores, which is caused by herpes simplex virus (usually type 1), canker are not caused by a virus. The cause is not clear, but can be triggered by stress, allergic reaction or nutrition deficiency. It can be associated with other diseases such as crohn's, celiac, behcet's or hiv.
Unsure. Canker sores r not usually caused by virus, unlike cold sores. The exact cause of canker sores r unknown. Some r thought due to stress, or trauma to the gum from braces or dentures. Certain vitamin deficiencies, such as vit b, zinc, folic acid, iron, or certain autoimmune diseases may be related.