A small blister grew at the corner of the mouth how to return a responsibility

Herpes simplex virus is a skin disease caused by herpes simplex virus infection. Herpes simplex virus has been latent in the human body, when the body resistance is normal, herpes simplex virus can not reproduce in large quantities, so it will not come on. When the body resistance is reduced, such as fever, cold or long stay up late, the virus will reproduce in large quantities, so herpes occurs. Herpes simplex occurs at the junction of skin and mucosa, such as lips, mouth, nostrils, etc. Therefore, herpes simplex will show the phenomenon of long blisters at the corners of the mouth. Herpes simplex is a relatively common skin disease, with self-limiting, normal about a week can heal, so do not worry too much.