Blisters at the corners of the mouth are very common in our lives and are a skin condition caused by herpes simplex virus infection from a Western medical perspective. In Chinese medicine, it is called hot sores, or fire. It manifests as localized blisters with burning and painful sensations. Western medicine treatment is anti-viral, while Chinese medicine treatment is evidence-based. The best choice for treatment of blisters in the corners of the mouth is Chinese medicine, because it is not a problem of a day or two, it is a manifestation of the constitution, and often people with a weak constitution are prone to grow, so the blisters will only grow when the constitution is weak after staying up late, pregnancy, radiotherapy, chemotherapy, and so on, and it will be much better to take Chinese medicine to regulate them. The common recurrent patients often belong to the yin fire evidence, fear of cold in winter, cold hands and feet, but easy on fire, the common method is to induce fire to return to the yuan, clear heat and detoxification, but there may be recurrent attacks. For external application, you can use Zijin ingot or Xinhuang tablet, both of which have the effect of clearing heat and detoxifying. Take a few of them and roll them into a paste with boiling water, and then apply them on the place with long blisters, usually it will be fine in two or three days, if the effect is not good, you should find a professional doctor in time.