The corners of the mouth can be treated with different medications depending on the cause, such as gentian violet or chloramphenicol and acyclovir. The corners of the mouth rot is a manifestation of xerostomia, accompanied by cracked corners of the mouth erosion or blistering. 1. Traumatic keratitis caused by trauma or physical irritation, you can use saline or chlorhexidine solution wet compresses, the affected area coated with gentian violet. 2. Infectious keratitis caused by bacterial, fungal and viral infections, according to the different pathogens of local medication, can use chloramphenicol, acyclovir and other coated. 3. Malnutrition type stomatitis can be oral vitamin B, gentian violet coated, keep the affected area clean and dry. So rotting corners of the mouth need to choose the appropriate medication according to the specific cause of the disease, you can go to the stomatology department. The medication should follow the doctor’s instructions.