Pseudogout

Question 1

Definition

Answer 1

Calcium pyrophosphate dihydrate disease

Due to the deposition of calcium pyrophosphate crystals leading to the inflammation of joints

Question 2

Risk factors

Answer 2

Increased age (most common)

Associated with conditions:
– hyperparathyroidism
– hypothyroidism
– hypomagnesemia
– hypophosphatasia

Question 3

Pathophysiology

Answer 3

Acute inflammation of joint:
– neutrophil-mediated phagocytosis of IgG tagged calcium pyrophosphate crystals
– release of inflammatory cytokines

polyarticular (affecting many joints)

slower onset than gout

duration- 3 weeks (less painful than gout, can resolve 7-10 days)

Self limiting

Question 4

Clinical presentation

Answer 4

Older adult with hot, swollen, stiff and painful knee

Other joints commonly affected:
– shoulders
– wrists
– hips

Question 5

Investigations

Answer 5

Aspirate fluid to diagnose whether its gout, pseudo gout or septic arthritis

Aspirated fluid will show:
– no bacterial growth
– calcium pyrophosphate crystals
– rhomboid shaped crystals
– positive birefringent of polarised light

Question 6

Treatment

Answer 6

Symptoms usually resolve spontaneously over several weeks.

Symptomatic management involves:
– NSAID’s
– Colchicine
– joint aspiration
– steroid injections
– oral steroids

Joint washout (arthrocentesis) is an option in severe cases