Pineapple is not recommended for mouth ulcers. Mouth ulcers are mainly manifested as a local burning sensation, pain, encounter a variety of irritating food pain will be aggravated, pineapple will produce stimulation of mouth ulcers, mouth ulcers are generally not allowed to eat pineapple. Pineapple itself is sweet and sour, mouth ulcers eat pineapple will stimulate the ulcers produce severe pain. In addition, pineapple has a large number of pineapple protease, can break down fibrin and blood clot, destroy the ulcer surface fiber healing, not conducive to the growth of epithelial tissue, thus delaying the healing of oral ulcers. Mouth ulcers can eat more fresh fruit without stimulation, such as watermelon, bananas and so on. If you like pineapple very much, you can eat a small amount of it, and rinse your mouth immediately after eating it to minimize irritation. In addition, you can use mouth ulcer film, ice boron powder and other medications applied locally to promote the healing of ulcers. Specific medication should be under the guidance of a doctor.