Acne at the corners of the mouth is mainly considered to be related to folliculitis, acne, herpes simplex, seborrheic dermatitis and other factors. 1. Folliculitis: caused by bacterial and fungal infections of the hair follicles, which can lead to acne-like lesions on the local skin, accompanied by redness, heat, itchiness, pain and other uncomfortable symptoms. 2. Acne: mainly caused by a variety of factors leading to hair follicle blockage, which can lead to pimples on the affected area, and with the development of the disease, pustules may be formed, and eventually form nodules. Once the pustules burst, scarring may form. 3. Herpes simplex: mainly caused by infection with the herpes simplex virus, which can lead to localized blisters, accompanied by painful symptoms. 4. Seborrheic dermatitis: the cause of this disease has not been fully clarified, can lead to local skin pimples, which can gradually develop into pimples, and some patients may be accompanied by itching and other uncomfortable symptoms. The appearance of the above symptoms, it is recommended to timely to the dermatologist, and follow the doctor’s instructions for appropriate treatment.