summary Gout is a form of inflammatory arthritis caused by intraarticular monosodium urate crystal deposition that typically presents with recurrent acute exacerbation of joint swelling and severe pain. Diagnosis is made by joint aspiration and crystal analysis showing strongly negatively birefringent needle-shaped intracellular crystals. Treatment for acute gout attacks is NSAIDs with chronic gout being treated with allopurinol and medical management to reduce uric acid. Epidemiology Demographics recurrent attacks seen in men from ages 40-60 years Anatomic location usually seen in lower limb podagra (arthritis attacks of great toe) crystal deposition as tophi ear helix, eyelid olecranon, Achilles tendon Risk factors chemotherapy Etiology Forms primary gout an idiopathic disorder of nucleic acid metabolism that leads to hyperuricemia and deposition of monosodium urate crystals in joints (a purine breakdown product) secondary gout is associated with a disease with high metabolic turnover (psoriasis, hemolytic anemia, leukemia, chemotherapy) Pathophysiology dysfunctional nucleic acid metabolism causing hyperuricemia deposition of monosodium urate crystals in synovium of joint crystals lead to an inflammatory response activating proteases prostaglandins leukotriene B4 free oxygen radicals Associated conditions renal stones septic arthritis the presence of uric acid crystals does not exclude septic arthritis Presentation Symptoms pain in joint can resemble septic arthritis symptoms of renal stones Physical exam may have decreased range of motion due to pain white toothpaste-like appearance of tophus aspirate Imaging Radiographs recommended views AP and lateral of affected joint findings may see punched out periarticular erosion with sclerotic overhanging borders may see soft tissue crystal deposition (tophi) Studies Labs serum uric acid elevated uric acid is not diagnostic (80% of people with an elevated uric acid will never have a gout attack) Crystal analysis diagnosis made by joint aspiration and crystal analysis monosodium urate (MSU) crystals are thin, tapered, needle-shaped intracellular crystals yellow when aligned parallel to red compensator blue when aligned across the direction of polarization strongly negatively birefringent Treatment Acute gout indomethacin vs. colchicine indications first line of treatment medications indomethacin (indocin) 50mg tid NSAID inhibits phagocytosis colchicine indicated in acute attacks if patient has a history of peptic ulcers inhibits inflammatory mediators can be given intravenously oral, intraarticular or IV glucocorticoid indication patient unable to take NSAID or colchicine Chronic gout allopurinol indications first line of treatment for chronic gout attack medications allopurinol is an xanthine oxidase inhibitor colchicine indications for prophylaxis after recurrent attacks up to 85% effective