This criteria set can be applied to patients that have synovitis in at least one joint and the absence of an alternative diagnosis. A total score of 6 or greater is diagnostic.

Primary nodal osteoarthritis (B) affects the hands. However, this answer is incorrect as the distal interphalangeal joints (DIPs) are usually more involved than the proximal interphalangeal joints (PIPs). In addition, pain is characteristically worse at the end of the day. Septic arthritis (C) usually presents as a monoarthritis, making this answer incorrect. Polymyalgia

rheumatica (D) is incorrect as this disorder is rare in those under the age of 60 and is characterized by pain and stiffness in the shoulders, neck, hips and lumbar spine, which is worse in the morning. Reactive arthritis (E) is usually an asymmetrical, lower-limb arthritis. Therefore this answer is also wrong.