Specific test for gout is:
|A||Raised serum uric acid level|
|B||Raised uric acid in synovial fluid of joint|
|C||X- Ray of Great toe|
|D||Raised urease enzyme level|
1. Gout (Ref. H 18th - Pg-2837)
i. Gout is a metabolic disease most often affecting middle-aged to elderly men and postmenopausal women, due to an increased body pool of urate with hyperuricemia.
ii. It is characterized by episodic acute and chronic arthritis, due to deposition of Monosodium urate crystals (AIPG 2009) in joints and connective tissue tophi.
iii. The risk for deposition in kidney interstitium or uric acid nephrolithiasis
iv. The metatarsophalangeal joint of the first toe is most commonly involved, (Small joints) but tarsal joints, ankles, and knees are also affected.
v. During acute attack the joint is very painful, red hot and swollen there is grade IV tenderness.
vi. Chronic gout patient may present with uric acid stone or tophi in skin or tubulo interstitial disease.
vii. Abrupt decrease in serum urate levels is more common a cause for acute gout than an abrupt increase in urate levels. Initiation of hypo uricemic therapy can precipitate acute attacks.
viii. Patient may be asymptomatic with high serum uric acid for years
i. Development of arthritis correlates with level of serum uric acid
Table : Classification of Hyperuricemia by Pathophysiology (H 17th Pg-2445)
1. Urate Overproduction
a. Primary idiopathic b. HPRT deficiency
c. PRPP synthetaseoveractivity d. Hemolytic processes
e. Lympho and myeloproliferative diseases f. Alcohol
g. Psoriasis h. Obesity
2. Decreased Uric Acid Excretion
a. Primary idiopathic b. Renal insufficiency
c. Hypothyroidism d. Hypertension
e. Acidosis f. Hyperparathyroidism
g. Drug ingestion (PGI June 08)
i. Salicylates, ii. Diuretics iii. Alcohol iv. Cyclosporine v. Ethambutol vi. Pyrazinamide
3. Combined Mechanism
a. Glucose-6-phosphatase deficiency
b. Fructose-1-phosphate aldolase deficiency
i. Best and the most specific test is analysis of synovial fluid - Uric acid crystals are best seen as needle shaped crystals by polarizing light microscope
ii. Serum uric acid levels are usually high but it can be normal or low at the time of the acute attack.