Talk to Dermatologist on Psoriasis

I have had psoriasis since I was 15. Previously I took methotrexate with folic acid to control it .

But now it is spread throughout my head and some parts of my body. I didn't have a problem with living with psoriasis. but now due to the fact that it's extremely spread on my head my hair is starting to fall to the extent that I'm going bald.

I really don't want to lose all my hair. Now I want to go back to methotrexate with folic acid, I just want to know the long term effects of taking methotrexate with folic acid.