Involved joints should be compared with their uninvolved opposites or with those of the examiner. Joint motion, generally painful in joint disease, may not be painful in periarticular, bone, or soft tissue disease. Swelling is an important finding. Monarthritis always suggests infection, crystal-induced arthritis, trauma, or rarely, tumor. Increased heat over the joint should be carefully localized.
Many normal joints are actually cooler than adjacent skin.
The main differential features of the hand in osteoarthritis and RA are outlined in Table 49-1. In Reiter's syndrome, synovial, periarticular, and periosteal changes can be present in a few DIP, proximal interphalangeal, or metacarpophalangeal joints, and there is asymmetric finger joint involvement. Findings in hypertrophic pulmonary osteoarthropathy include clubbing of the fingertips and bony tenderness of the distal radius and ulna caused by underlying periostitis. Joint synovitis similar to that in RA occurs in SLE and, less often, in dermatomyositis, although arthralgias and sore, painful hands lacking objective joint swelling are more typical of both these disorders. Finger deformities resembling RA can occur in SLE but are caused by soft tissue disease, not advanced erosive arthritis.