What causes cold sores at the corners of the mouth?

Herpes on the corner of the mouth is usually caused by infection with the herpes simplex virus (HSV), which is divided into two types: HSV-1 and HSV-2. HSV-1 primarily causes herpes around the lips, while HSV-2 is usually associated with genital herpes. However, both types of the virus can cause herpes lesions on any part of the body. Herpes on the corner of the mouth is a common oral condition, and its main causes include the following:

1. Weakened immune function: When a person's immunity is low, they are more susceptible to various bacterial infections, which may lead to herpes outbreaks.

2. Bacterial infection: Poor personal hygiene can lead to bacterial infection in the corner of the mouth, potentially forming pustules that resemble herpes lesions.

3. Viral skin diseases: Particularly invasion by the herpes simplex virus, is a common cause of herpes on the corner of the mouth. This virus typically resides in the trigeminal ganglion and tends to recur when the patient has a fever or local wounds.

4. Other factors: Burns, vitamin deficiencies, and angular cheilitis may also lead to herpes on the corner of the mouth.

Treatment includes the use of antiviral medications to reduce the severity and duration of symptoms, as well as maintaining good personal hygiene practices, avoiding sharing utensils and personal items with others to reduce the risk of transmission.