Mouth ulcers should not be punctured with a needle, because on the surface of the ulcer, a pseudomembrane is usually formed to protect the ulcer surface from cold, hot, sour, sweet, or spicy irritating food to ensure that the mucous membrane of the deep ulcer tissue, so do not use a needle to puncture the mouth ulcer when it occurs. In addition the degree of sterilization of the needle is not guaranteed, usually the needles that can be found at home are bacterial, so once the needle picks through the mouth ulcer surface, it may cause secondary infection, making the ulcer surface aggravated, increasing the pain level more, and also delaying the healing of the mouth ulcer. So when mouth ulcers appear, it is recommended that patients should apply some topical medication on the area of the mouth ulcer, and not easily pick it with any sharp instrument.