My 90 Year Old Father Has Rheumatoid Arthritis, High Blood

My 90 year old father has rheumatoid arthritis, high blood pressure and developed a swelling on his forehead extending to his top of the head, it is red and painful. He also has a raised temperature, over 38 C. He also was very itchy all over for a couple of weeks. He also had a hormone injections for his prostate 3 months ago due to higher PSA. He has not been well since and has a very poor appetite.