Gout and Pseudogout Differential Diagnoses

Updated: Aug 27, 2017
  • Author: Bruce M Rothschild, MD; Chief Editor: Herbert S Diamond, MD  more...
  • Print
DDx

Diagnostic Considerations

The cause of new-onset acute monoarticular arthritis cannot be reliably determined from the history and physical examination alone. Septic arthritis, gout, and pseudogout can present in very similar ways.

Nevertheless, certain clinical presentations are so characteristic of gout that attempts have been made to diagnose or exclude gout without joint aspiration. Janssens et al developed a diagnostic rule for this purpose, which included the following diagnostic criteria [88] :

  • Male sex
  • Previous arthritis attack
  • Onset within 1 day
  • Joint redness
  • First metatarsophalangeal joint involvement
  • Hypertension or 1 or more cardiovascular diseases
  • A serum uric acid level higher than 5.88 mg/dL

In a study of this rule in 328 patients, the positive predictive value of gout diagnosis by family physicians was 0.64; the negative predictive value was 0.87. [88]

Nevertheless, the criterion standards for the diagnosis of gout remain the following:

  • Demonstration of intracellular monosodium urate crystals
  • Exclusion of infection or other crystal types in the synovial fluid from the inflamed joint

Patients who present with acute inflammatory arthritis need to undergo arthrocentesis to exclude septic arthritis, even if their serum uric acid level is elevated. Nongonococcal infectious arthritis carries a 10% fatality rate and therefore must be excluded.

Other problems to be considered in the differential diagnosis of gout and pseudogout include the following:

  • Acute sarcoidosis
  • Amyloidosis
  • Bursitis
  • Calcific periarthritis
  • Chondrocalcinosis
  • Congenital fructose intolerance
  • Conjunctival calcinosis
  • Hyperparathyroidism
  • Hypoxanthine-guanine phosphoribosyltransferase deficiency (Lesch-Nyhan syndrome)
  • Malignant soft tissue tumors
  • Milk-alkali syndrome
  • Multicentric reticulohistiocytosis
  • Paronychia
  • Pigmented villonodular synovitis
  • Phosphoribosylpyrophosphate synthetase superactivity
  • Psoriatic arthropathy
  • Reactive arthritis
  • Renal osteodystrophy
  • Spondyloarthropathy
  • Rheumatoid arthritis
  • Tenosynovitis
  • Trauma
  • Type IIA hyperlipoproteinemia

Differential Diagnoses