Terrible pain in arms and legs, low grade fever pain bad enoigh cannot bear weight at times.family history psa & ra could it be rheumatology issue?15yr old

Definitely could be : From what you describe and family history, this indeed could be a rheumatologic problem. Based on other history and physical findings, i could think tick borne disease or rheumatic fever. Have a doctor evaluate and order appropriate blood work, and refer as needed.

Possible: At age 15 the most likely cause would be jia or fibromyalgia. With jia there should be swelling and not just pain. With fibromyalgia there should be a history of poor sleep and no fever. I would recommend you see your family doctor or someone experienced with this type of problem for a definite diagnosis.

Yes: Could definitely be a rheumatology issue. Could be jia (juvenile idiopathic arthritis- either associated with psoriasis or not). Could be other things non-rheumatologic (infection, etc) with the fevers. Definitely see a physician with these complaints!