Reason of joint pain

by Nathan Wei, MD, FACP, FACR

Nathan Wei is a nationally known board-certified rheumatologist and author of the Second Opinion Arthritis Treatment Kit. It's available exclusively at this website... not available in stores.

Click here: Second Opinion Arthritis Treatment Kit

Generally, joint pain can be attributed to three main sources.

• Injury
...including trauma, a fall, a twist or overloading of a joint that causes minor damage to the joint. With injury, people generally experience temporary inflammation and pain.
• Degenerative arthritis or osteoarthritis
... frequently found in the hips and knees of people in their 60s and 70s, but also as early as 40 years old. This type of arthritis causes pain based on wear and tear of the joints.
• Inflammatory joint disorders
... When the capsule holding the fluid that lubricates the joint becomes inflamed and painful, inflammatory joint disorder is likely the reason. Types include rheumatoid arthritis, gouty arthritis and infectious causes like Lyme disease.

Polyarticular joint pain (pain in more than four joints) poses a diagnostic challenge because of the extensive possibilities. Consequently, one needs to keep the diagnosis open in evaluating patients who present with pain in multiple joints.

Because many rheumatologic laboratory tests lack the desired specificity, results should be interpreted in the clinical context and with caution.

In the absence of definitive rheumatologic laboratory tests, the history and physical examination are key to the early diagnosis and treatment of conditions that cause polyarticular joint pain. The differential diagnosis can be narrowed through investigation of six clinical factors: disease chronology, inflammation, distribution, extra-articular manifestations, disease course, and patient demographics . More common causes of polyarticular joint pain should be considered first.

Acute polyarticular joint pain (pain that has been present for less than six weeks) may be the sign of a self-limited disorder or a harbinger of chronic disease. Although chronic polyarticular arthritides more often develop insidiously, they can present abruptly. Thus, chronic conditions such as rheumatoid arthritis and systemic lupus erythematosus should be considered, at least initially, in patients who present with acute polyarticular joint pain To avoid treating a self-limited disorder with potentially toxic disease-modifying agents, synovitis probably should be present for six weeks before rheumatoid arthritis is diagnosed- but not always!

Viruses (e.g., human parvovirus B19, hepatitis viruses), crystals, and serum sickness reactions are known causes of acute, self-limited polyarthritis. The specific cause of virus-induced arthritis is not always investigated; thus, the prevalence of viruses as the etiology of arthritis may be underestimated.

With the exception of Neisseria gonorrhoeae, direct bacterial infections in joints seldom cause polyarthritis. Although typically oligoarticular, extra-articular bacterial infections may induce acute arthritis. Classic reactive arthritis is associated with enteric infections (Salmonella, Shigella, Campylobacter, or Yersinia species) and urogenital infections (Chlamydia trachomatis).

Early gout usually affects only one joint. However, this disease also should be considered in patients with acute polyarticular arthritis, particularly older women who are taking diuretics and have hypertrophy and degenerative changes of the distal interphalangeal (DIP) joints (Heberden's nodes) and proximal interphalangeal (PIP) joints (Bouchard's nodes).

Arthritis is joint pain with inflammation, whereas arthralgia is joint pain without inflammation. The patient who presents with psoriasis and knee pain in the absence of inflammation may have the dual diagnosis of psoriasis and osteoarthritis. However, the patient who also has inflammation probably has psoriatic arthritis, which may require more aggressive therapy. Inflammatory arthritides include infectious arthritis, gout, rheumatoid arthritis, systemic lupus erythematosus, and reactive arthritis.

Cardinal signs of inflammation include erythema, warmth, pain, and swelling. Patients with severe joint inflammation or systemic disease also may present with fatigue, weight loss, or fever. Morning stiffness lasting longer than one hour suggests underlying inflammation. The duration of morning stiffness provides a useful guide to the extent of inflammation. For instance, morning stiffness associated with rheumatoid arthritis may last for hours. Palpation of multiple joint capsules is important to look for soft tissue swelling and effusions that result in edema and influx of inflammatory cells into and around the synovium. Soft tissue swelling should be distinguished from non-inflammatory bony hypertrophy, such as Heberden's and Bouchard's nodes, which often indicate osteoarthritis. Crepitus indicates the presence of irregularities of the articular cartilage, which most commonly are associated with osteoarthritis, injury, or previous inflammation.

Because findings can be subtle, it is important to palpate each hand joint. Although palpation often can identify synovitis, it may not detect inflammation of more proximal joints in, for example, elderly patients with polymyalgia rheumatica. Morning stiffness and a history of swelling suggest an inflammatory process but also are characteristic of fibromyalgia, a noninflammatory condition. Typically, patients with fibromyalgia have a subjective sense of swelling but no objective signs of synovitis. Fibromyalgia is suggested by the presence of polyarticular joint pain without synovitis, along with myalgias and tender points.

The pattern of joint involvement provides diagnostic clues. Spondyloarthropathies typically involve the larger joints of the lower extremities. Osteoarthritis tends to spare wrists, elbows, and ankles, unless there is a history of trauma, inflammation, or a metabolic disorder such as hemochromatosis.

Depending on the underlying cause, the pattern of arthritis may change over time. For example, the acute stage of Lyme disease may include polyarticular arthralgias, whereas the chronic phase may include oligoarthritis, primarily in the knees.

Joint involvement tends to be symmetric in systemic diseases such as rheumatoid arthritis, systemic lupus erythematosus, polymyalgia rheumatica, viral arthritides, and serum sickness reactions. Of eight variables examined in one study, symmetric pain was the most potent discriminating feature for rheumatoid arthritis. Psoriatic arthritis, reactive arthritis, and gout are more likely to present with asymmetric peripheral involvement.

Axial pain may be a helpful indicator in the evaluation of peripheral joint pain. In addition to peripheral joints, osteoarthritis may involve the lower back, the neck, or both. In contrast, rheumatoid arthritis is seldom an explanation for low back pain.

Extra-articular manifestations may provide clues to the presence of some rheumatologic diseases but, of themselves, are not diagnostic. For instance, extra-articular signs and symptoms can point to the likely reason for swollen PIP joints: a malar rash and oral ulcers indicate probable systemic lupus erythematosus; proximal muscle weakness suggests polymyositis; and psoriatic skin and nail lesions raise the possibility of psoriatic arthritis.

Similarly, in a patient with knee arthritis, the presence of conjunctivitis, oral ulcers, vesicopustules on the soles, or recent diarrhea may indicate reactive arthritis. A history of erythema chronicum migrans and Bell's palsy points to the diagnosis of Lyme disease. As a final example, a health care worker who presents with fever, a lacy rash, and symmetric joint pain (especially in the hands) may have erythema infectiosum caused by human parvovirus B19 infection.

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