Any other odd, seemingly unrelated symptoms? Such as muscle aches, eye pain, chronic headaches, bowell issues, glands in neck sore? Can you pinpoint a date of severe illness causing this?
Do you have psoriasis? Dont know about having both types but you can certainly have psoriasis and be diagnosed with rheumatoid arthritis, indeed autoimmune diseases like to keep company with each other. A person can be negative for the rheumatoid factor for a while and then become positive which could cause confusion if you already have skin psoriasis when the joint pain starts, however both are treated similar so as long as you are getting treatment, thats the important part.