Methotrexate
"I have had psoriasis since I can remember, last year after a foot injury I developed psoriatic arthritis. Since it has spread to both feet, both knees, one hand and lower back. Leaving me hardly being able to walk at 30. I started methotrexate 4 weeks ago and it is helping a lot. Only side effects for me are fatigue.

I do 1 ml injections once a week.  If you have PsA, get on methotrexate. If you can handle the needles injections are the way to go."