I Have Psoriatic Arthritis In My Hands And Feet But

I have psoriatic arthritis in my hands and feet but recently have been having a lot of swelling and pain in my right knee. The swelling is on the inside of my knee, the pain is an ache below my knee cap and this weekend I started having numbness on the skin on top of my knee and a burning sensation on the outside of my knee (especially after walking and going upstairs)