What should I do if I develop cold sores at the corner of my mouth?

Herpes lesions at the corners of the mouth are typically caused by herpes simplex virus (HSV) infection—a viral disease. Therefore, antiviral therapy is generally the first-line treatment.

Topical antiviral agents such as penciclovir cream are commonly used; oral antiviral medications—including acyclovir, valacyclovir, and ganciclovir—may also be prescribed concurrently.

In addition to these conventional treatments, traditional Chinese medicine (TCM) or proprietary Chinese herbal medicines with heat-clearing and detoxifying properties may be used as adjunctive therapy. Commonly selected proprietary TCM preparations include Qingre Jiedu Syrup, Lan Qin Oral Liquid, and Pu Di Lan Oral Liquid. During treatment, patients should ensure adequate rest, avoid staying up late, and refrain from consuming spicy or irritating foods.