The causative agent of canker sores is overwhelmingly Staphylococcus aureus, but may also be hemolytic streptococcus, E. coli, and others. To identify the causative agent of canker sores, tissue fluid or pus is collected for bacterial culture and drug sensitivity testing. The purpose of bacterial culture is to identify the causative organisms and select sensitive drugs according to the drug sensitivity test of the causative organisms. If the carbuncle grows particularly large and the surface has obvious fluctuating sensation, you can choose surgical incision and drainage to eliminate pus and discharge necrotic tissues, together with anti-inflammatory drugs for treatment, and will soon be relieved. At the same time of treatment, try to avoid spicy and stimulating diet, can not drink alcohol.