Pseudogout (CPPD): Symptoms, Causes, Treatment
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Pseudogout describes inflammatory joint attacks associated with calcium pyrophosphate crystals. It differs from uric-acid gout and can resemble joint infection, which must be considered.
What is Pseudogout (CPPD)?
Calcium pyrophosphate deposition includes more than acute attacks: deposits may be asymptomatic or associated with chronic arthritis. Knees are commonly affected, but wrists and other joints can be involved.
Related reading: Joint infection: another cause of acute swelling.
Symptoms
Severe pain, swelling, warmth and restricted joint movement can begin abruptly and recur. Appearance alone cannot distinguish a flare from gout or infection.
Causes
Crystals form in cartilage and may trigger inflammation. The reason is often unknown; mineral or endocrine disorders and inherited factors contribute in some people.
Risk factors
Older age, previous joint injury or surgery, hyperparathyroidism, low magnesium and iron overload are risk factors. Earlier-onset disease warrants consideration of associated metabolic or inherited conditions.
Diagnosis
Joint aspiration may identify crystals and test for infection, supported by selected imaging and blood tests. Crystals do not exclude simultaneous infection; raised uric acid does not diagnose CPPD.
Treatment
Anti-inflammatory medicines, colchicine or corticosteroids are selected for kidney function, interactions and clinical circumstances; drainage may help. No established treatment dissolves CPP crystals, and urate-lowering drugs do not treat them.
Complications
Recurrent attacks or chronic inflammation can affect cartilage and mobility. Preventive treatment and follow-up depend on flare frequency and coexisting conditions.
Prevention
Addressing associated disorders and recurrent attacks may reduce the burden. Do not automatically adopt a gout diet or avoid dietary calcium; discuss nutrition and medication with your clinician.
When to see a doctor
A newly hot swollen joint needs prompt assessment, especially with fever or systemic illness. Do not assume a familiar flare or receive a steroid injection before infection is excluded.