Crystal arthropathy

Question 1

Define Crystal arthropathy

Answer 1

Big joints-usually big toe or knee
Gout-uric acid/crystals
CalciumPyroPhospahte/Pseudogout-less common

Gout-uric acid is from purine nucleotides (2/3 from metabolism, 1/3 diet)-and humans only excrete them via kidney and gut. If take to much (not even that much)-> crystallise, stimulate acute inflam

Question 2

Signs and Sx of Crystal arthropathy

Answer 2

gout-short acute history--Very often MTP joint
Joint pain, severe with tenderness
stiffness
Tenderness
Very red, warm, tender
TOPHI - white spots on ears and elbows

in soft tissue, uric acid deposition can cause tophi-

CCP-knees and wrists affected . older women
Looks very similar to GOUT

Question 3

Investigations of Crystal arthropathy

Answer 3

Gout-
Uric acid might be high
Inflam markers high

Xray-early on nada
later-periarticular erosion (rat bite-like a chunk taken out of side

CPP-positive birefringement
gout-negative birefringement

Question 4

management Crystal arthropathy

Answer 4

Acute gout---
1st line -any off 3, till 2d post resolve
Max dose NSAID
Colchicine
Short course steroid (3-5d)
dont stop allopurinol

follow up 4-6w after

Refer for complications (? septic, 2ndary cause, tophi)

For prevention- Start 2-4w after acute
reduce purine intake (avoid BEER, anchovies, offal, etc)
Review medication

Start low dose
1st line Allopurinol/Febuxostat (don’t ever stop, even during flare)
Aim urate under 360mmol

offer prophylactic colchicine when titrating as can cause acute flares
Annual monitoring

Pseudo-
flare treat same, but nothing for prevention