Hi,
How are you? Are there other symptoms present? Recurrent mouth ulcers can occur in a number of patients. The cause of recurrent mouth ulcers is often unknown and factors such as anxiety, oral trauma, medication effect, and hormonal changes may increase the chances of getting them. Also, around 40% of people who have recurrent mouth ulcers have a family history of the condition. Underlying medical conditions to be contributory include Vitamin B12 deficiency, iron deficiency, celiac disease, Crohn's disease, reactive arthritis, and immunodeficiency. These should also be ruled out by your doctor. Take care and best regards.
You may well exclude Takahara's disease( Acatalasia), benign condition with absent catalase enzyme. These patients may present with recurrent oral ulcers.