The diagnostic criteria for rheumatoid arthritis are that the patient first has wandering painful swollen peripheral large joints, mainly in the knee, elbow, shoulder and ankle joints. The joint swelling and pain are self-limiting, but tend to recur, and the pain is not followed by joint ankylosis, deformity and joint space changes. The diagnosis of rheumatoid arthritis is clear if the patient has the above characteristics of swollen and painful joints and there is evidence of streptococcal infection, such as the presence of an elevated ASO. Rheumatoid arthritis is an inflammation of the joints induced after infection with group A beta-hemolytic streptococci, so to treat rheumatoid arthritis, a full course of anti-infective treatment is required, commonly benzathine penicillin is used.