I have Psoriatic Arthritis & am suffering with constant mouth sores?

If you want to stop the mouth ulcers, stop taking methotrexate. methotrexate immunosuppression your body can not fight common bacteria's including air born, that’s why you can catch common colds are flue like symptoms all year around. i am still surprised that doctors still prescribe this drug for human beings, when you would not give it to an animal.

I have been taking methotrexate for RA since Oct. of 09. I get the mouth sores as well. I was taking folic acid for a year to control the mouth sore issue. It quite helping so now I take Leucovorin, I still get them but not as much or as often. Might ask your doctor about taking something to help with the side effect of mouth sores that come from taking the methotrexate. I hope you get some help.

I also have Psoriatic Arthiritis. When I was on oral Methotrexate, I had terrible mouth sores. They were on my gums, the insides of my cheeks and at the back of my mouth. When I was switched over to the injection Methotrexate, I didn't have this problem anymore. I've noticed some comments about folic acid fixing this problem, but my rheumatologist has had me on extra folic acid all along.

Hi Kathy. Sorry to hear of your issue! I can sympathize. I was on Methotrexate & had horrible ulcers as well as burning sensations whenever I ate spicy food (which is a majority of my diet)! My Dr had prescribed Folic Acid that I never took until someone told me that it would relieve the ulcers. They were right! I can't remember what the dose was but you may want to try an OTC (& maybe check w/ the pharmacist to see what a safe but high dose would be) until you can get back to your Dr to get a RX. Hope this helps. Be Well!~Wendy

Taking Methotrexate does cause canker sores as its side effects, although canker sores could also be caused as a disease.

Would recommend that you read more details on this link: http://www.emedicinehealth.com/canker_sores/article_em.htm, sympathize with you condition & wish you all the best, & a speedy recovery, please bear it, take care, be safe & well.