I believe that many people have the experience of blisters on the lips and mouth, this is not simply “fire”, Western medicine called herpes simplex. Herpes simplex is a viral skin disease characterized by clustered blisters caused by herpes simplex virus (HSV) infection. The disease is somewhat self-limiting, but is prone to recurrent episodes. Humans are the only natural hosts of HSV. Primary infections occur in children up to 5 years of age and are often subclinical (i.e., without clinical symptoms.) HSV can be present in blister fluids, oral and nasal secretions, and can be transmitted by direct or indirect contact. When the body resistance drops (such as fever, cold, exertion, pregnancy, menstruation, etc.), the latent virus is activated to migrate to the skin and mucous membranes innervated by the nerve to appear herpes recurrence. Clinical manifestations: can be divided into primary herpes simplex and recurrent herpes simplex, primary infection lesions relatively wide range, self-conscious symptoms are more obvious, the course of the disease is longer. Primary herpes simplex includes: herpetic gingivostomatitis, neonatal herpes simplex, inoculative herpes simplex, herpetic eczema, herpetic keratoconjunctivitis, disseminated herpes simplex and so on. Common typical manifestations: the rash occurs in the lip margin, corners of the mouth, around the nostrils and other skin-mucous membrane junction. At the beginning of the local skin itching, burning or tingling, and then appeared pinhead or rice grain size cluster blisters, blisters thin wall, blister liquid clear, blisters are generally not fusion, can be self ulcerated, vesicles, oozing, and gradually dry and crust. Treatment: local topical antiviral ointment (such as acyclovir cream, etc.); with bacterial infection, antibiotic ointment can be used (such as fusidic acid cream, mupirocin ointment, etc.); vesicles oozing, with 3% boric acid solution wet compress. Oral nucleoside antiviral drugs (acyclovir, famciclovir, vasiclovir, etc.). Prevention: avoid exertion, mental stress, exercise to improve immunity.