How is calcium pyrophosphate dihydrate crystal deposition disease (CPPD, or pseudogout) diagnosed?
CPPD cannot be diagnosed simply from a blood test. It is diagnosed by the study of fluid from the inflamed joint, which is observed under a microscope for CPPD crystals.
Fluid is aspirated through a needle from the inflamed joint. This procedure is called arthrocentesis. Removing the fluid may also help reduce the pressure within the joint and thereby reduce pain.
Since different types of crystals in the joint can be the cause of other forms of arthritis, it is important that an accurate diagnosis be made. Then, your doctor can prescribe the appropriate treatment.
The diagnosis of CPPD can be suspected by certain X-rays and imaging studies, but the findings of CPPD crystals on synovial fluid analysis leads to a more definite diagnosis.