<s>[INST] I am 46 years of age, 5 ft 3 in tall and am in good overall health. Approximately two years ago, I was at the beacChatDoctoring out of my room, located on the 3rd or 4th floor, I was stung by something and immediately turned around and went back to the room. The sting or bite was painful, swelling up to my knee. I was bit or stung on my left foot leaving a three-prong bite or sting mark on my foot. I immediately put benedryl creme on my foot up to my knee. Some of the swelling went down after an hour or so. But it was still painful and swelled. I was ok for the rest of the trip [/INST] Hi, The effect of sting or bite remaining for 2-3 years is not possible, these are usually antedating event which leads to unmasking of underlying pathology cause for knee swelling and pain may be infective or inflammatory in origin. You need to get a complete blood count along with arthritic profile, and if required after the results of blood tests knee aspiration and testing to be done furthermore to make a diagnosis. Take care. Hope I have answered your question. Let me know if I can assist you further.  </s>