This is a picture of aphthous ulcers which are often confused with cold sores, but they are not caused by the herpes virus. Apthous ulcers can occur anywhere in the mouth but do not involve the outside of the lip. Someone who has herpetic stomatitis (herpes ulcers throughout the mouth caused by an initial oral herpes infection) may have ulcers in the mouth, but they will typically have cold sores on the lip also.
Aphthous ulcers can be caused by a number of factors:
- Coxsackievirus - one of the viruses that causes colds and hand, foot, and mouth disease
- Autoimmune diseases - Crohn's disease, ulcerative colitis, and Behcet's syndrome
- Contact dermatitis - aspirin, strong mouthwashes, spicy foods, citrus
- Chemotherapy medications