Hi, welcome to our site. I am Dr Saumya Mittal. Read your query. That is a very significant question and i appreciate your problem. I will try my best to answer your query there are many other possible causes of having developed the pain and swelling with redness granted that with the sudden onset, i would have probably thought about gout as the first probability too however now that you say the uric acid levels were normal, i would suggest we think about the other possibilities like rheumatoid arthritis. the fact remains that without seeing the lesion, it will be difficult for me to comment on what this possibly could be i would therefore take the help of tests and suggest the following a. rheumatoid factor b. esr c. x ray of the affected joint d. a repeated test of uric acid meanwhile i would suggest you stay off high protein diet I hope this helps you. Inform the reports mentioned above so i can be of help further. Best of luck. I have given you the answer to the maximum considering the information provided. The results of the tests could further enhance my answer to you. Please do understand that some details could be extracted from a detailed history and examination. Looking forward to your return query with the details asked so that I can help you further. (If the answer has helped you, please indicate this)