Pseudogout & Reactive Arthritis Flashcards
What is pseudogout?
A form of microcrystal synovitis caused by the deposition of calcium pyrophosphate dihydrate crystals in the synovium.
CPPD disease
What are some risk factors for pseudogout?
1) haemochromatosis
2) hyperparathyroidism
3) acromegaly
4) low Mg, low phosphate
5) Wilson’s disease
What joints are most commonly affected in pseudogout?
1) knee
2) wrist
3) shoulders
What does joint aspiration show in pseudogout?
1) positively birefringent
2) rhomboid shaped crystals
Mx of pseudogout?
1) exclude septic arthritis (joint aspiration)
2) NSAIDs or intra-articular, intra-muscular or oral steroids as for gout
What is reactive arthritis?
A rare systemic inflammatory disorder arising 1-6 weeks after a GI (Salmonella, Shigella Campylobacter) or urogenital infection (Chlamydia trachomatis).
What group of conditions does reactive arthritis belong to?
A group of seronegative spondyloarthropathu.
Also includes psoriatic arthritis, ankylosing spondylitis, and arthritis due to IBD.
What gene does reactive arthritis have an association with?
HLA-B27
What is the main genitourinary pathogen that can cause reactive arthritis?
Chlamydia trachomatis
What GI pathogens can cause reactive arthritis?
1) Salmonella
2) Enterobacteria
3) Shigella
4) Campylobacter
Clinical features of reactive arthritis?
1) arthritis (often asymmetric oligoarthritis)
2) urethritis e.g. dysuria, urinary frequency, and discharge
3) conjunctivitis
‘Can’t see, pee or climb a tree’
How long after initial GI/genitourinary infection does reactive arthritis develop?
typically within 4 weeks
What skin manifestations may be seen in reactive arthritis? (2)
1) Keratoderma blennorrhagicum –> waxy yellow rash/hyperkeratotic lesions on soles of feet
2) Circinate balanitis –> erythematous plaques on the glans penis.
What does an XR show in pseudogout?
Chondrocalcinosis
