GOUT Flashcards
Which joint is most commonly affected by gout?
The metatarsal phalangeal joint.
Apart from the MTP, which other joints are commonly affected by gout?
Ankle Foot Small joint of the hand Wrist Elbow Knee
Define gout.
An inflammatory arthritis caused by the deposition of monosodium urate crystals into the joint space.
Why is the first MTP joint the most likely joint to be affected by gout?
Pressure effects of walking on the joint, leading to increased likelihood of osteoarthritis and reduce blood supply.
Most distal part of the body, therefore coldest part.
Is gout more often a monoarthritis or a polyarthritis?
A monoarthritis, but it can be a polyarthritis.
What is the underlying pathology of gout?
Urate crystal deposition
What causes the redness of the affected joint?
Neutrophils
What might someone with more chronic polyarthritic gout present with?
Gout tophi
Is gout a systemic disease?
Sort of. Both joints and skin are affect by tophi. You can also get urate a crystals forming in the tubules and ureter in the kidney.
Is high serum urate enough to diagnose gout?
No. It just increases the likelihood that the pathology is gout.
Does gout more commonly affect males and females?
Males
What is the ratio of males to females?
Roughly 4:1
Where is urate excreted?
Kidneys
What are some of the causes and risk factors associated with gout?
Hereditary Increase of dietary purines, including beer, offal meat and shell fish Diuretics Leukemia treated with cytotoxics Hypertension Diabetes Chronic renal failure Aspirin increases the urate serum levels
What must be excluded when investigating any inflammatory monoarthritis?
Septic arthritis
What is the diagnosis differential for a patient presenting with the signs and symptoms of gout?
Haemoarthrosis
CPPD
Pseudogout
Palindromic rheumatoid arthritis
What are the investigations needed to make a diagnosis of gout? For each investigation state what result would indicate a positive diagnosis of gout.
Polarised light microscopy of synovial fluid shows negatively birefringent urate crystals.
Serum urate is usually high, but this is not enough to diagnose gout.
Radiographs in early stages will show only soft tissue swelling. In later stages, well defined ‘punched out’ erosions are seen in the juxta-articular bone.
What might you not see on a radiograph of a joint affected by gout that you might see on a radiograph of a joint affected by osteo or rheumatoid arthritis?
Reduced joint space
Sclerotic reactions
What is the medical treatment of gout?
NSAIDs
Coxib
Steroids
Colchicine
Why might NSAIDs be problematic in some gout patients?
Renal failure
What lifestyle changes are recommended in order to prevent the return of gout?
Reduce alcohol intake
Change diet to avoid purine rich meat
Reduce dose of aspirin
How might someone with suspected gout present?
Severe pain
Often in a single joint - most often the MTP
The joint will be very red
The joint will be swollen and oedematous
How are urea and urate related?
They aren’t really, except that they both get their name from urine.
What shape are crystals of monosodium urate?
Needle shaped, about the width of a cell.
Where do tophi normally form?
Most often in the joint and subcutaneous tissue
Also in the helix of the ear
Sometimes in bone
How do tophi in the bone present on a radiograph?
Clearly defined holes either at the joint margins or within the shafts of small bones.
Can gout be inherited?
Defects in urate metabolism can be inherited and this may lead to juvenile gout.
What is the severe syndrome which results from a defect in urate metabolism?
Lesch-Nyhan syndrome
Name three features other than gout of Lesch-Nyhan syndrome.
Mental retardation
Self-mutilation
Renal failure
