Crystal Arthritis Flashcards
What is gout?
Inflammatory disease where monosodium urate crystals deposit in the joints making them red, hot, tender and swollen
What type of crystals are found in gout?
Monosodium urate crystals
Does gout usually present with monoarthropathy or polyarthropathy?
Does it occur in intermittent or continuous episodes
Monoarthropathy
Occurs in intermittent episodes
Does gout affect men or women more commonly
Men x6 and rises in post-menopausal women
What condition do we need to exclude when someone presents with a red, how, swollen, painful joint?
Septic arthritis.
Symptoms / presentation of gout. Most common joint gout occurs in?
50% occur at the metatarsophalangeal joint of the big toe = podagra.
In podagra, patient will typically wake up in the middle of the night with severe toe pain and burning sensation
Other common joints: knee, ankle, foot, small joints of hands, wrist and elbow
What is causing the pain felt in gout?
WBCs infiltrating the joint to remove uric acid and releasing pro-inflammatory cytokines.
What things can precipitate an attack of gout?
- trauma
- surgery
- starvation and dehydration
- infection
- diuretics
- alcohol or shellfish. binge
- most attacks are spontaneous
Risk factors for gout
excess urate production and reduced urate excretion
Reduced urate excretion:
- Impaired renal function - uric acid excreted by kidney so problems put them at risk for gout
- Diuretics (Thiazide)
- Aspirin
- Elderly
- Men
- Postmenopausal women
- HTN
- Metabolic syndrome
- Antihypertensives
Excess urate production
- Hyperuricaemia
- Dietary (alcohol - beer, fructose sweeteners, red meat, seafood, organ meat)
- Genetic disorders
- Myelo-and lymphoproliferative disorders
- Psoriasis
- Tumour lysis syndrome where tumour is broken down rapidly and can cause increased uric acid leading to gout
- Drugs (alcohol, warfarin, cytotoxics)
What things are included in the metabolic syndrome? (8)
heart disease lipid problems hypertension T2DM dementia cancer POS NAFLD
Investigations for gout
Usually a clinical diagnosis but joint aspiration can be used to confirm.
Bloods
- Inflammatory markers
- Uric acid taken between episodes of gout
- Joint aspiration will confirm the diagnosis with polarised light microscopy of synovial fluid showing negatively birefringement urate crystals
- X rays can show punched out holes in bones
Treatment of gout
General advice: rest, elevate, ice packs
First line: colchicine or NSAIDs if colchicine CI - co-prescribe PPI if giving. NSAID
Second line: steroids or intra-articular injection of steroids (prednisolone)
Prevention of gout & urate-lowering drug
Weight loss, avoid prolonged fasting
Avoid excessive alcohol. and purine rich foods and low dose aspirin.
Urate lowering drug: allopurinol is first line if more than 1 attack per year
Goal = get uric acid <300,
How does allopurinol / febuxostate work?
Allopurinol and febuxostate are xanthine oxidase inhibitors stopping production of uric acid
What is pseudogout?
Who does it affect & what other condition does it over lap with?
Type of arthritis which causes similar symptoms to gout yet is formed by different crystal types (calcium pyrophosphate) which triggers the reaction.
Commonly affects elderly and overlaps with osteoarthritis.
