Rheumatoid Arthritis
Rheumatoid arthritis can be diagnosed in some cases simply by inspecting the hand, even when no nodules are present. First, there may be interosseus atrophy, best noted by inspecting the dorsum of the hand in oblique lighting, but with practice, discernible in direct light. Weakness of the interossei results in inability to forcefully extend the interphalangeal joints, which is necessary for finger-flicking movements. Second, there is ulnar deviation of the hand and the fingers. The best fingers to check for ulnar deviation are the third and index fingers, as many normal older persons will appear to have mild ulnar deviation of the other fingers. In severe carpal rheumatoid arthritis, however, all the fingers show a clear ulnar deviation.
It is worth remembering that rheumatoid arthritis of the wrist tends to spare the radial side of the joint. In fact, a severe arthritis of the wrist that spares the ulnar side and vigorously attacks the radial side is likely to be osteoarthritis (degenerative joint disease). Also remember that classic rheumatoid arthritis never attacks the distal interphalangeal (DIP) joints.
Other manifestations of rheumatoid arthritis include (a) loss of grip strength; (b) limited flexion in one or more fingers due to nodular tenosynovitis (felt as a small movable nodule in the flexor tendon as you passively flex and extend the joint); (c) vasculitic lesions, which may herald serious systemic vasculitis (
Weiss, 1984); and (d) Haygarth nodes (actually not nodes but fusiform synovial swellings of the proximal interphalangeal [PIP] joints).
Dr Gerry Rodnan of Pennsylvania made the diagnosis of rheumatoid arthritis by squeezing the metacarpal heads during a handshake (
Rodnan et al., 1973). This can be quite painful for the patient. If you suspect this diagnosis, it is better not to shake hands but simply to ask what would happen if you were to squeeze the patient’s hand.
The American College of Rheumatology criteria for the diagnosis of rheumatoid arthritis are given in
Table 24.2. Although the criteria focus on joint manifestations, remember that rheumatoid arthritis is a systemic disease (see
Chapter 10 for eye findings).
Generalized symptoms such as fatigue, weight loss, malaise, and depression are also common (
Lee and Weinblatt, 2001).
Although the patient’s and the doctor’s attention may be focused on the peripheral joints, the cervical spine is affected early in the course of rheumatoid arthritis, even within the first two years (see
Chapter 25). This is for some reason strongly correlated with involvement of the carpal and metacarpophalangeal (MCP) joints (K. Smith,
personal communication, 2009) and with erosions in the bones of the hands and feet (
Winfield et al., 1983). Wasting of the forearm and hand muscles may result from compression of the anterior spinal artery at upper and mid cervical levels (
Mathews, 1998).
Osteoarthritis
This “degenerative,” seronegative arthritis produces characteristic nodules of the DIP joints called Heberden nodes. These feel like two little dried split peas placed subcutaneously on the lateral and medial dorsal surface of the finger at the DIP. When they are present on the PIP joint, they are called Bouchard nodes. Osteoarthritis tends to spare the MCP joints.
Scleroderma
The American College of Rheumatology criteria for the diagnosis of progressive systemic sclerosis require the presence of
proximal scleroderma (skin tightness) or the presence of two of three other criteria. These criteria are
Proximal is defined as above the wrists by the American College of Rheumatology, and above the elbows by various others. The criteria were designed for research and thus exclude individuals in whom the disease is not fully expressed. Scleroderma skin changes above the MCP or metatarsophalangeal (MTP) joints are 91% sensitive and 99.8% specific for definite scleroderma (
Wigley, 2001).
Nail-fold capillary changes are described in
Chapter 7.
Patients with sclerodactyly alone have some or all of the features of the CREST syndrome, and it has been argued that this syndrome should be called “limited scleroderma.” The CREST syndrome includes calcinosis, the Raynaud phenomenon (see
Chapter 18), esophageal dysmotility, sclerodactyly, and telangiectasia.
New criteria have been proposed for early diagnosis and classification on the basis of advances such as the identification of scleroderma (anticentromere) autoantibodies and other advances (
LeRoy and Medsger, 2001). Disease manifestations are variable and complex. The use of a term such as “undifferentiated connective disease with features of scleroderma” has been suggested as a hedge against overdiagnosis and overly aggressive treatment (
Wigley, 2001).
Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) is a multisystem disease diagnosed by a combination of clinical and laboratory criteria. The American College of Rheumatology diagnostic criteria are given in
Table 24.3. Always remember that diseases do not necessarily fit precisely into authoritatively defined pigeonholes. In particular, there are many more neurologic manifestations, both central and peripheral, that have been attributed to lupus. These include demyelinating disorders, chorea, Guillain-Barré syndrome, myasthenia gravis, and autonomic disorders (
Ruiz-Irastorza et al., 2001).
Almost all patients experience arthralgias and myalgias, and most develop intermittent arthritis. Pain is often out of proportion to physical findings. Characteristically, there is symmetric fusiform swelling of joints, most frequently the PIP and MCP joints and the wrists and knees. Diffuse puffiness of hands and feet, and tenosynovitis, may be seen. In contrast to rheumatoid arthritis, joint deformities are unusual, with only 10% of patients developing swan-neck deformities of the fingers and ulnar drift at MCP joints. Erosions are rare. Subcutaneous nodules occur.
A careful drug history is mandatory. Drugs that have been associated with SLE are listed in
Table 24.4. The syndrome is rare except with procainamide (the most common offender) and hydralazine, and is probably related to genetically determined drug acetylation rates.
Gout
Tophi occur more frequently on the ears and feet, and when present on the hand (
Fig. 24-1), though highly suggestive of gout, could be initially confused with a rheumatoid nodule. Definitive diagnosis is made by joint aspiration and demonstration of urate crystals (see
Chapter 28). Presence of a tophus is 33% sensitive and 93% specific for gout.
Hemochromatosis
Patients with hemochromatosis are prone to a degenerative type of arthritis that can affect the hands and fingers as well as the joints of the lower extremities. The PIP joints of the middle and ring fingers may be affected, mimicking the Haygarth fusiform swelling of rheumatoid arthritis confined to those joints.