Hello,

Gout is due increased uric acid accumulation in body either due to increased production or impaired excretion through kidneys. Usually effects elderly men and women and presents as acute or chronic arthritis (joint inflammation and pain). Acute attacks are very painful and occur episodically following heavy meal or alcohol consumption. Initially it affects big toe joint (metatarsophalyngeal joint) by accumulation of needle shaped MSU(Monosodium urate) crystals called tophi in joint space. These tophi are also subsequently accumulated in other joints like knee causing pain.

Diagnosis of gout is usually done by needle aspiration of these MSU crystals from joint space and examining them in parallel polarized light under which they appear yellow. Serum uric acid levels are not always reliable in diagnosis as they can be normal or low during acute attacks and also after initiating treatment with uric acid lowering drugs like Allopurinol or Probenecid. However subsequent tests may reveal increased uric acid levels in blood following acute attacks. These levels are observed to know the effect of treatment as less than 5mg/dl is usually the target of treatment to prevent recurrent attacks.

There is another disease commonly referred to as pseudo-gout which has similar clinical presentation as gout but it is due to accumulation of CPPD (Calcium pyrophosphate dehydrate) crystals. These crystals appear blue in parallel light and serum uric acid is usually normal. Acute attacks of both gout and pseudo-gout are treated by Glucocorticoid injections and colchicines but hypouricemic drugs are specific for Gout and useful in effective treatment.

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