#4 Herpes Simplex
Herpes is a stubborn viral infection that can cause breakouts of sores on your body in various parts – oral herpes showing sores on the face and mouth, and genital herpes resulting in sores on the genitals. It is trasitted by unprotected sexual contact such as oral sex or intercourse.
While doctors can prescribe treatments to heal the sores, the virus stays inactive in your body throughout your life and never goes away. But int he future, certain conditions like stress can trigger an outbreak again.