Mouth herpes is one way of referring to herpes symptoms that appear about the mouth. Mouth herpes is more typically referred to as oral herpes, or cold sores. Mouth herpes is usually caused by a Herpes Simplex Virus 1, or HSV 1, infection. HSV 1 is exceptionally common, affecting up to ninety percent of the adult population. HSV 1, like HSV 2, is spread through skin-to-skin contact. Mouth herpes doesn't always present symptoms, but when it does it's usually referred to as cold sores or less commonly, fever blisters. Various treatments for mouth herpes are available in both prescription and nonprescription form.