Gout Flashcards
Gout : Definition
Inflammatory disease of a joint, due to monosodium urate crystal deposition - causing pain and swelling.
Gout : Pathophysiology
Gout : Pathophysiology
- Purines are components of DNA/RNA - when cells are broken down, those purines are converted into uric acid
- Uric acid can then be filtered out of the blood and excreted in the urine
- Uric acid has limited solubility in bodily fluids
- Uric acid binds to sodium when in excess in the body resulting in insoluble monosodium urate crystals
Gout : Causes of Hyperuricaemia
-
Increased consumption of purines - purine high foods such as shellfish, anchovies and red meat
* High fructose corn syrup can increase formation of uric acid by increasing purine synthesis -
Dehydration/increased alcohol consumption/ kidney disease- decreases clearance of uric acid via the kidneys
* Above diet can lead to obesity and diabetes - assoc with Gout - Chemotherapy can increase cell apoptosis resulting in increases purines released - leading to hyperuricaemia
- Thiazide diuretics + Aspirin increase uric acid levels
Gout : Clinical features
- 1st metatarsal joint of the foot, also effects ankles, knees, wrists and elbows
- Hot, swollen and tender
- Very painful, and Burning sensation, ++ sensitive
- Attacks last for several hours, discomfort and swelling can last for days
Gout : Complications
1 . Tophi
* Recurrent gout attacks -> permenant urate crystal deposition
2 . Urate nephropathy and Uric acid kidney stones
Gout : Diagnosis
- Aspiration and analysis of synovial fluids - negatively birefringent monosodium urate crystals under polarised light
- Blood test : uric acid levels
- X-ray : Joint effusion, punched out erosion with sclerotic margins,
Gout : Management
Acute and long term management
1 . Lifestyle advice:
* Reduce alcohol intake, lose weight, change diet to avoid high purine foods.
* Stop percipating drugs: thiazide diuretics - consider losartan instead,
* Increase vitamin C as this also decreases uric acid levels
Acute flare mx -
1 . NSAIDs, Naproxen - give with PPI
2 . Colchicine
3 . Oral/IA steroid
Maintainance Mx
1 . First line : Allopurinol
2 . Second line : Febuxostat
Gout : Acute Mx
First line : NSAID or Colchicine
Second line : If both CI
* 15mg prednisolone
- Iniate Allopurinol once inflammation has settled after the first attack of gout
Gout : SE of Colchine
- Renal impairment
* Reduce dose if eGFR<50
* Avoid if <10 - Diarrhoea
Gout : Longterm Mx
- Allopurinol
Indic : Initiated after first attack of gout - once initial inflammation has cleared
* Do not discontinue after starting if has another attack of gout
* Colchine cover alongsider starting Allopurinol
Mx :
* Initial dose 100mg - titrate until serum uric acid level <360
Gout : Triggering drugs
- diuretics: thiazides, furosemide
- Asprin
- ciclosporin
- alcohol
- cytotoxic agents
- pyrazinamide
Pseudogout : Pathophysiology
- Inflammation of the synovium
- Deposition of calcium pyrophosphate dehydrate crystals in the synovial fluid.
Pseudogout : Risk factors
- Haemochromatosis
- Hyperparathyroidism - 3. Raised calcium levels
Pseudogout : Diagnosis
- Joint aspiration : weakly positive birefringent rhomboid shaped crystals
- X-ray : Chondrocalcinosis, linear calcifications of the meniscus and articular cartilage can be seen.
