Pineapple is generally not recommended for patients with mouth ulcers. 1. Mouth ulcers refer to the destruction of the epithelial layer of the oral cavity, forming depressions or turning into ulcers, and generally mouth ulcers have the symptom of mucosal defects. 2. Pineapple is rich in vitamin C, moderate consumption of pineapple can replenish the body of vitamins, is conducive to promote the healing of mouth ulcers, so mouth ulcers are not prohibited to eat pineapple. However, when consuming pineapple, the acid in pineapple will stimulate the mucous membrane defects, which will cause pain, so it is not recommended to consume pineapple. 3. If necessary, mouth ulcers can be treated with medication, common drugs include lidocaine, benzocaine, 0.05% chlorhexidine gargle, compound chlorhexidine solution, etc. The medication should be carried out under the guidance of a doctor. 4. Mouth ulcer patients in the daily diet, should eat more rich in vitamin C, vitamin B₁, vitamin B₂, vitamin E and zinc-containing food, is conducive to the healing of ulcers, drink more water, avoid spicy and stimulating food, quit smoking, quit drinking. Mouth ulcer patients should actively cooperate with the treatment, follow the doctor’s instructions to do a good job of care, so as not to cause adverse reactions, the use of drugs need to follow the doctor’s instructions.