Hi all, A bit confused here. I am suffering mouth ulcers, under my tongue, on the cheeks and around inside my lips. Having read a few past blogs, folic acid may be the cause, but some blogs say that their folic was upped when they got ulcers. So there is a mixed response. I am also on methotrexate. Can anyone shed any light on this. I have recently had a cold which seemed to last ages, whereas I used to be able to shift a cold quite quickly. Either the bugs are getting stronger, or my immunity is not so good now.