Gout / Pseudogout Flashcards
Where do we get urate from
Purines in DNA and diet
What does HGPRT do
Salvage DNA bases so purine is not made
What causes overproduction of urate
Malignancy Myeloproliferative disorder Drugs - Warfarin Alcohol HGPRT deficiency (Lesch Nyan) Exercise Psoriasis
What causes under excretion of urate
Renal impairment / CKD Hypertension Hypothyroid Drugs - diuretics Exercise Starvation / dehydration Lead poisoning as affects kidney Aspirin but not if cardioprotective
What is LEsch Nyan syndrome and how is it inherited
HGPRT deficiency X-linked recessive Intellectual disability Aggressive Gout Renal disease Self mutilation
What is gout and what can precipitate
Deposits of monosodium urate crystals in joints
Causes inflammatory response
Trauma Surgery Starvation Infections Diuretics
What are the RF for gout
Men Women after menopause as oestrogen protective Age due to reduced renal Renal impairment Obesity DM High cholesterol High BP Alcohol Diureitcs Dehydration Surgery INfection
How does gout present
Acute monoarthrtis (60% big toe MTP) Can occur in ankle, foot, hand, elbow Occurs overnight Red, painful, hot and shiny - looks septic Swelling Tophi can build up (uric crystals in soft tissue) Lasts 7-10 days Symptom free between
What are the renal complications of gout
Radiolucent stones
Interstitial nephritis
How do you Dx gout and what does microscopy show
Aspiration + gram stain + culture (to exclude infection)
Polarised light microscopy shows -ve bifringenet needle shaped crystals
Increased urate in blood
X-Ray
What does X-ray show
Joint effusion Lytic lesion Erosions + sclerosis Joint space loss = late sign NO OSTEOPENIA (RA) Soft tissue tophi or swelling
How do you treat an acute flare up of gout
Aggressive Ax till SA excluded
NSAID = 1st line (may need PPI)
Colchicine = 1st line if NSAID CI
Oral / IM steroids if both CI e.g. if renal failure etc.
Intra-articular steroid injection can be used
What must you make sure
Kidney function okay
DDX of gout
Septic arthritis Pseduogout OA Haemarthrosis Reactive arthritis Cellulitis Bursitis
When do you treat prophylactically 1st attack of gout
Polyarticular Tophi Urate calculi in kidney Renal insufficiency Cytotoxic / diuretics Lesch Nyan
When do you usually give prophylaxis
2nd attack within 1 year or prior to Rx of malignancy
How do you lower uric acid
Allopurinol (xanthine oxidase inhibitor) = 1st ilne
Uricosuric agent = Lorsartan
When do you start
Once attack has settled as can often worsen
Wait 2 weeks
NSAID / colchicine cover should be used when starting
What must else you do
Address CVS / lifestyle Reduce alcohol Weight loss Avoid high purine foods Increase vit C Review drugs and consider stopping diuretics etc
What is calcific periarthritis
Deposit of calcium phosphate hydroxyl-apatite
What is pseudgout
Deposits of calcium pyrophosphate dehydrate
What are the symptoms of pseudogout
Erractic flares of acute monoarthropathy
Flares usually last weeks with months in between in contrast to gout which last days
Associated OA
Affects knee and wrist like gout affect toe
Who is at risk
Elderly female Age OA DM Hypothyroid Hyperparathyroid Haemochromatosis Wilson Acromegaly HypoMg / phosphate
How do you Dx and what does miscropscy show
X-ray Joint aspiration to exclude SA Light microscopy - +ve Bifrigent rhomboid blue crystal Bloods for cause - U+E, iron, PTH, TFT Blood culture
