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Polyarticular arthralgia can originate from arthritis, or from extra-articular disorders (eg, polymyalgia rheumatica, fibromyalgia).

Arthritis can be inflammatory or noninflammatory (eg, osteoarthritis). Inflammatory arthritis may involve peripheral joints only, or both peripheral and axial joints. Inflammatory arthritis involving ≤ 4 joints is termed peripheral oligo- or pauciarticular arthritis. Involvement of > 4 joints is called peripheral polyarticular arthritis. Each of these types has specific, likely causes (see Table 3: Approach to the Patient With Joint Disease: Common Causes of Polyarticular Arthritis).

Table 3
Common Causes of Polyarticular Arthritis Peripheral polyarticular RA SLE Viral arthritis Serum sickness Psoriatic arthritis Peripheral oligoarticular Behçet's disease Enteropathic arthritis Infective endocarditis Gout (or pseudogout) Psoriatic arthritis Reactive arthritis Rheumatic fever Lyme disease arthritis Peripheral with axial involvement Ankylosing spondylitis Enteropathic arthritis Psoriatic arthritis Reactive arthritis

Often, arthritis is transient and resolves without diagnosis or may not fulfill the criteria for any defined rheumatic disease; a tentative diagnosis may be made so that treatment can proceed. Systemic disease should be considered in all atypical and undiagnosed conditions.

Evaluation

Clinical data, particularly the history, are the most powerful diagnostic tools.

History: The location of symptoms may reveal whether pain originates in joints or other structures such as bones, tendons, bursae, muscles, other soft-tissue structures, or nerves. In arthritis, an inflammatory disorder is suggested by prominent morning stiffness, nontraumatic joint swelling, and fever or weight loss. Pain that is diffuse and described inconsistently or vaguely may result from fibromyalgia or functional disorders.

Back pain with arthritis suggests a spondyloarthropathy such as ankylosing spondylitis. Arthritis with urethral or GI symptoms suggests reactive arthritis. Recurrent diarrhea or abdominal pain suggests arthritis complicating inflammatory bowel disease.

Physical examination: Fever, wasting, or rashes may reflect systemic rheumatic or nonrheumatic disorders. Musculoskeletal examination should first determine whether the problem is intra-articular and, if so, whether it is inflammatory. Long-standing arthritis can restrict passive joint motion.

Periarticular findings may help differentiate among disorders. For example, coexisting tendinitis is common in gonococcal arthritis, RA, and other systemic diseases; bone tenderness may be prominent in sickle cell disease and hypertrophic pulmonary osteoarthropathy. Other extra-articular findings may also suggest a specific type of arthritis (eg, tophi in gout, rheumatoid nodules in RA).

Examination of the hand may help differentiate between arthritides. The main differential features of the hand in osteoarthritis and RA are outlined in Table 4: Approach to the Patient With Joint Disease: Differential Features of the Hand in Rheumatoid Arthritis and Osteoarthritis. Swan-neck or boutonnière deformities may result from chronic RA. Distal interphalangeal (DIP) joint involvement with pitting in the adjacent nail and slightly asymmetric involvement of other joints may suggest psoriatic arthritis. Asymmetric involvement of the fingers may represent reactive arthritis, and asymmetric DIP joint involvement plus tophi suggests chronic gout. Thickening of the skin and flexion contractures may indicate progressive systemic sclerosis. Raynaud's phenomenon suggests progressive systemic sclerosis, SLE, or mixed connective tissue disease. Clubbing of the fingertips and bony tenderness of the distal radius and ulna caused by underlying periostitis can occur in hypertrophic pulmonary osteoarthropathy. Sore, painful hands with few objective abnormalities often represent SLE and, less often, dermatomyositis, although in these disorders there may also be joint synovitis similar to that in RA. Scaling erythema over the extensor joint surfaces, especially over the knuckles, may indicate dermatomyositis.

Table 4
Differential Features of the Hand in Rheumatoid Arthritis and Osteoarthritis Criteria Rheumatoid Arthritis Osteoarthritis Character of swelling Synovial, capsular, soft tissue; bony only in late stages Bony with irregular spurs; occasional soft cysts Tenderness Usual None or mild except during occasional acute onset Distal interphalangeal involvement Not usual, except in thumb Usual Proximal interphalangeal involvement Usual Frequent Metacarpophalangeal involvement Usual Unusual Wrist involvement Usual or common Rare, except in base of thumb metacarpal-carpal joint Adapted from Bilka PJ: Physical examination of the arthritic patient. Bulletin on the Rheumatic Diseases 20:596–599, copyright 1970. Used by permission of The Arthritis Foundation.

Testing: If the specific diagnosis cannot be established clinically and if determining whether arthritis is inflammatory will help determine the diagnosis, ESR and C-reactive protein may help. Elevated results suggest inflammation but are very nonspecific, particularly in older adults. Other tests may be needed for diagnostic dilemmas.

Last full review/revision November 2005

Content last modified November 2005