But don’t confuse canker sores with cold sores or fever blisters, which are sores caused by the herpes simplex virus and found outside the mouth around the lips, on the cheeks or chin, or inside the nostrils. Oral herpes blisters — Herpes lesions are quite different from canker sores, although they too can be very painful. They are typically presented as small, red blisters on your lips. These are canker sores, the cold sores caused by oral herpes, and the chancre sores caused by syphilis. (It doesn’t help that chancre rhymes with canker, so sometimes people aren’t certain exactly what their doctor has said.
Canker Sores: The main cause of 1 or 2 mouth ulcers after age 5. Herpes Virus (Cold sore virus): The first infection can be severe and cause 10 or more ulcers on the gums, tongue and lips. Treatment will come later. How can you treat the sore unless you KNOW whether it’s a canker sore or herpes? Find out now!