Pseudogout (calcium pyrophosphate deposition disease, CPDD)

• What is Pseudogout (Calcium pyrophosphate deposition disease)
• Statistics on Pseudogout (Calcium pyrophosphate deposition disease)
• Risk Factors for Pseudogout (Calcium pyrophosphate deposition disease)
• Progression of Pseudogout (Calcium pyrophosphate deposition disease)
• Symptoms of Pseudogout (Calcium pyrophosphate deposition disease)
• Clinical Examination of Pseudogout (Calcium pyrophosphate deposition disease)
• How is Pseudogout (Calcium pyrophosphate deposition disease) Diagnosed?
• Prognosis of Pseudogout (Calcium pyrophosphate deposition disease)
• How is Pseudogout (Calcium pyrophosphate deposition disease) Treated?
• Pseudogout (Calcium pyrophosphate deposition disease) References

What is Pseudogout (Calcium pyrophosphate deposition disease)

As the name suggests, pseudogout is not true gout but often causes symptoms that closely resemble those of gout. Pseudogout is caused by the deposition of calcium pyrophosphate crystals in cartilage (often referred to as calcium pyrophosphate deposition disease – CPPD). These may precipitate acute and painful inflammation in the affected joint.

Statistics on Pseudogout (Calcium pyrophosphate deposition disease)

The frequency of pseudogout increases with age, usually occuring in individuals over 50 years. It occurs slightly more frequently in women. There is no preference in terms of ethnicity.

Risk Factors for Pseudogout (Calcium pyrophosphate deposition disease)

The incidence of pseudogout rises with age, and is rare before 30 years. A family history of pseudogout increases risk, as do prior joint injury or surgery, hyperparathyroidism and haemochromatosis.

Progression of Pseudogout (Calcium pyrophosphate deposition disease)

Pseudogout may be divided into a number of categories:
1) sporadic – no apparent predisposing factors
2) hereditary – there is a family history of the disease, symptoms tend to manifest earlier
3) secondary – linked to a history of joint injury or certain metabolic conditions such as hyperparathyroidism, haemochromatosis, diabetes and hypothyroidism.

How is Pseudogout (Calcium pyrophosphate deposition disease) Diagnosed?

The diagnosis is made by viewing positively birefringent crystals in fluid taken from the affected joint under a microscope. Calcification of the cartilage made be seen on x-ray.

Prognosis of Pseudogout (Calcium pyrophosphate deposition disease)

Prognosis is good for acute episodes of psuedogout, which usually improve over a period of 10 days or so. Currently it is not known how to prevent or reverse joint damage caused by chronic disease.

How is Pseudogout (Calcium pyrophosphate deposition disease) Treated?

Treatment consists of removing the fluid from the joint, corticosteroid injections and anti-inflammatory drugs to reduce pain and swelling. Currently there is no known way of removing the crystals already present in the joint and tissues.

Pseudogout (Calcium pyrophosphate deposition disease) References

[1] Apley G. Concise system of orthopaedics and fractures, 2nd ed. 2001 Arnold.
[2] Collier, Longmore, Scally. Oxford handbook of clinical specialties, 6th ed. 2003, Oxford University Press.
[3] Doherty M: Calcium pyrophosphate deposition disease and other crystal deposition diseases. Curr Opin Rheumatol 1990 Oct; 2(5): 789-96
[4] Kaplan J, Gout and Pseudogout. emedicine 2004 http://www.emedicine.com/emerg/topic221.htm (online)
[5] Kumar and Clark. Clinical Medicine 5th ed. 2002. WB Saunders.