Pseudogout

a.k.a. “Calcium Pyrophosphate Dihydrate (CPPD) Crystal Deposition Disease”
  • or “Chondrocalcinosis”
Onset usually around or >65 y.o.
  • Knee is most common; other large- & medium-joints too
Patterns
  • May occur in flares (mimics gout)
  • May be chronic progressive (mimics osteoarthritis)
  • Rarely mimics RA (attacks of multiple-joint arthritis, morning stiffness, lasting months)

Diagnosis

**  Crystals in joint fluid (may be hard to find)
  • Either “positively bifringent” or “not bifringent”
  • urate crystals of gout are “negatively bifringent”
**  Joint X-Ray:
  • CPPD crystal deposition noted in cartilage or joint
  • Radiology may report other findings “consistent with CPPD disease”
After Diagnosis:  Screen for Other Conditions associated w/ Pseudogout
  • Hemochromatosis
  • Hyperparathyroidism
  • Hypophosphatasia
  • Hypomagnesemia
  • Hypothyroidism
  • Gitelman’s syndrome (low K+, Ca++, and Mg++)

See posting Monoarticular Arthritis.

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