Herpes simplex virus infection is mainly caused by herpes simplex. It is a viral infection of the skin and is divided into herpes simplex type I and herpes simplex type II. Type I occurs mainly on the face, especially on the lips and mouth, and around the nose. The typical manifestation of herpes simplex is a cluster of small blisters on an erythematous base, usually the size of a grain of rice to a green bean, and the contents are usually clear. However, sometimes it can be more cloudy and more easily ruptured, after which the surface will form a vesicular surface, followed by crusting. Sometimes the symptoms are mild, but sometimes there is a burning or itching sensation, and the duration of the disease is usually one to two weeks. Type II occurs more often in the genital area and is similar to type I. It can also be painful and itchy. Herpes simplex generally has a quicker course but is prone to recurrence, especially in immunocompromised patients, and recurrences may be more frequent.