Had to put a note in after reading your posts. I have psoriatic arthritis and it varies in many ways from Rheumatoid and Osteo, but all have the same outcome. My joints in my fingers, knees, elbows, toes and my spine have all deteriorated in the past two years, since having psoriassis. I am now registered disabled and find the disease very frustrating and annoying.
Osteo is simply wear and tear, whereby Rheumatoid and Psoriatic are inflammatory diseases. I take immunosuppressants, painkillers and have just had depro medrone steroid injection to make me feel better for christmas. Psoriatic arthritis is not to be taken lightly, some people get it midly others, much more seriously. It doesn't go, they just try hard to make it better for you. If you have any more questions please post, I will try to help.