GOUT
Gout once called the “Disease of Kings” is also seen in Women, Especially After MenopauseGout: tophus, hand
Gout: footGout: tophi, hand
Gout: tophi of the pinna, earGout of distal interphalangeal joints simulating osteoarthritis
GOUT
Gout is a true crystal deposition disease. It can be defined as the pathological reaction of the joint or periarticular tissues to the presence of monosodium urate monohydrate (MSUM) crystals.URATE, HYPERURICEMIA & GOUT
Urate: end product of purine metabolism Hyperuricemia: serum urate > urate solubility) 6.8 mg/dlThe prevalence of gout varies between populations but is around 1% with a strong male predominance (> 10:1). Prevalence increases with age and increasing serum uric acid concentration. 'Primary' gout is almost exclusively a male disease and the most common cause of inflammatory arthritis in men over the age of 40..
HYPERURICEMIA & GOUT
Hyperuricemia caused by 10% Overproduction Underexcretion 90%Classification of Hyperuricemia
1- Uric acid overproduction Acquired disorders : Ethanol deficiencyMyeloproliferative disorders Cytotoxic chemotherapyGenetic disorders: Deficiency HGPRT(hypoxanthine-guanine phosphoribosyl transferase), or superactivity of PRPP(phosphribosyl pyrophosphate synthetase).
Uric acid underexcretion Accounts for >90% of hyperuricemia Diminished tubular secretory rate, increased tubular reabsorption, diminished uric acid filtration
2-
Hyperuricemia
Overproduction (10%) Ethanol HGPRT or G6PD deficiency PRPP synthetase overactivity Myeloproliferative disorders Cytotoxic chemotherapyUnderexcretion (90%) Renal insufficiency Drugs and toxins Diuretics Ethanol Cyclosporine A Pyrazinamide Lead nephropathy Low-dose aspirin Ketosis
Serum uric acid levels are distributed in the community as a continuous variable Levels are higher in men than women; they rise from the twenties in men and after the menopause in women, positively correlate with obesity, and vary according to ethnicity.
Estrogen have a mild uricosuric effect; therefore, gout is unusual in premenopausal women Higher renal clearance of urate in women possibly due to their higher plasma estrogen levels
Pathogenesis of Gouty Inflammation
Urate crystals stimulate the release of numerous inflammatory mediators in synovial cells and phagocytes The influx of neutrophils is an important event for developing acute crystal induced synovitisGOUT RISK FACTORS
Male Postmenopausal female Older Hypertension Pharmaceuticals: Diuretics, ASA, cyclosporineGOUT RISK FACTORS
Transplantation Alcohol intake Highest with beer Not increased with wine High BMI (obesity) Diet high in meat & seafoodClinical features
1- Acute gouty arthritis extremely rapid onset, reaching maximum severity in just 2-6 hours, often waking the patient in the early morning severe pain, often described as the 'worst pain ever' extreme tenderness-the patient is unable to wear a sock or to let bedding rest on the joint marked swelling with overlying red, shiny skin .. .
During the attack the joint shows signs of marked synovitis but also periarticular swelling and erythema. There may be accompanying fever, malaise and even confusion, especially if a large joint such as the knee is involved. As the attack subsides, pruritus and desquamation of overlying skin are common. The main differential diagnosis is septic arthritis, infective cellulitis or another crystal disease.
After an acute attack some people never have a second episode; in others the next episode occurs after years. In most, however, a second attack occurs within 1 year and the frequency of attacks gradually increases with time. Later attacks are more likely to involve several joints and to be more severe
2-Chronic tophaceous gout Large MSUM crystal deposits produce irregular firm nodules ('tophi') at the usual sites for nodules around extensor surfaces of fingers, hands, forearm, elbows, Achilles tendons and sometimes the helix of the ear. The white colour of MSUM crystals may be evident and permits distinction from rheumatoid nodules.
TOPHI
Solid urate deposits in tissuesTOPHI
Irregular & destructiveGout: tophi, hands
3- Progressive renal disease is an important complication confined to untreated severe chronic tophaceous gout. This results from MSUM crystal deposition in the interstitium of the medulla and pyramids with consequent chronic inflammation, giant-cell reaction, fibrosis, glomerulosclerosis and secondary pyelonephritis…Renal stone ..
Investigations Definitive diagnosis requires identification of MSUM crystals in the aspirate from a joint, bursa or tophus. In acute gout synovial fluid shows increased turbidity due to the greatly elevated cell count (> 90% neutrophils..
SYNOVIAL FLUID
polarizing microscopyAssessment of renal function (serum creatinine, urine testing), hypertension, blood glucose and serum lipid profile should be undertaken. An FBC and ESR should detect myeloproliferative disorders during remission of acute gout. During an attack a marked acute phase response (elevated CRP, neutrophilia) is usual; the ESR is often modestly raised in tophaceous gout
X-rays can assess the degree of joint damage. In early disease they are usually normal, but narrowing of joint space, sclerosis, cysts and osteophyte (changes of OA) may develop in affected joints with time, or be present as a predisposing factor in secondary gout. Gouty 'erosions' (bony tophi) are a less common but more specific feature occurring as para-articular 'punched-out' defects with well-delineated borders and retained bone density. Tophi may also be visible as eccentric soft tissue swellings..
Gout: hand (radiograph)
RADIOLOGIC SIGNSX-RAYS
ManagementThe acute attack A fast-acting oral NSAID (. Indomethacin 50 mg 4hourly. naproxen, diclofenac,) can give effective pain relief and is the standard treatment. Patients can keep a supply of an NSAID with which they are familiar and take it as soon as the first symptoms are noticed, continuing for the duration of the attack.
. Oral colchicine (a potent inhibitor of neutrophil microtubular assembly) can be very effective, but unfortunately often causes vomiting and severe diarrhoea at the doses needed for rapid relief (1 mg loading dose, then 0.5 mg 6-hourly until symptoms abate). The compromise is to try lower doses (0.5 mg 8-12-hourly) for a slower onset of benefit. Aspiration of the joint will give instant relief and, when combined with an intra-articular corticosteroid injection to prevent fluid reaccumulation, often effectively aborts the attack
Correction of any predisposing factors should always be attempted. Lifestyle alteration to correct obesity and reduce excess beer consumption may significantly reduce hyperuricaemia. Diuretics should be stopped if possible. Although a very high purine diet (large amounts of seafood, red meat and offal) should be tempered, there is no need for a specific highly restrictive diet. and trigger acute attacks.. .