Introduction
Gout is a crystalline inflammatory disease, due to monosodium urate monohydrate crystals deposition in the joint and tissues.
It is a common form of arthritis that causes intensive pain, swelling and stiffness in the joints.
It is due either to excessive uric acid production from intrinsic purine metabolism or extrinsic (dietary).
Due to decrease renal excretion of uric acid and resultant accumulation in the blood.
It is commonly seen in males (40 years and above) and post menopausal females
Types
4 major types
- Asymptomatic
- Acute
- Inter critical
- Chronic Tophaceous
It could be either primary (no identifiable cause) or secondary.
Secondary causes include:
- Dehydration
- Fasting
- Renal impairment
- Hypertension
- Malignancy such as lymphoma, leukemia
- Psoriasis
- Sickle Cell Disease
- Use of cytotoxic agents
- Excessive alcohol intake especially beer
- Low dose Aspirin
- Drugs such as Pyrazinamide, Diuretics
Clinical Presentation
- Usually mono-articular, occasionally Polyarticular (in elderly persons and in renal failure)
- Sudden onset of pain and swelling
- Pain and swelling maximal within 24-48 hours
- Tendency to start at night or early hours of the morning
- Usually follows binge of alcohol or consumption of offal of animals
- Recurrent painful episodes
- Affects big toe (Podagra), but also large joints-forefoot, ankles, knees, wrists.
- There may be associated fever, vomiting, diaphoresis, rigors
Chronic Tophaceous Gout
- Follows long standing attacks of acute gout, usually up to 7 years
- Tophi deposit in the skin, ear lobes, over joints
- Tophi may deposit in the kidneys and brain
Differential Diagnosis
- Septic Arthritis
- Osteoarthritis
- Rheumatoid arthritis
- Gonococcal arthritis.
- Traumatic synovitis
- Pseudogout
- Osteomyelitis.
- Reactive Arthritis.
Investigations
- Serum Uric Acid- may be normal in acute Gout
- Haematocrit, white blood cell count,
- ESR
- Creatinine, Urea- to exclude associated renal impairment
- Cholesterol, Triglycerides- usually coexist with Gout
- Plasma glucose (high serum uric acid may be a component of metabolic syndrome)
Treatment objectives
- Treatment of pain
- Lower Serum Uric Acid to below 6mg/100ml
Non-drug treatment
- Dietary control avoid offal, salmon, sea food, red meat
- Avoid alcohol especially beer, wine
- Reduce weight
- Control cholesterol level
- Avoid tight shoes
- Rest affected joints
- Avoid surgical operation of tophi
Drug Treatment
Acute Gout
NSAIDs at higher doses above normal
- e.g. Naproxen-500mg tds
- Diclofenac-75mg BD
- Prednisolone – 40mg daily for 1 week then taper quickly and stop
Intra articular steroids
Triamcinolone
- 5- 40 mg by intra articular/ intradermal injection
according to patient’s size (maximum 80 mg), may be
repeated when relapse occurs
Or:
Methylprednisolone
- 4- 80 mg (depending on patient’s size) intra articularly; may be repeated at intervals of 7-35 days
Chronic Tophaceous Gout
Oxidase Inhibitor
- Allopurinol – gradual escalation from 100mg daily up to 600mg daily
Uricosuric agent
Sulfinpyrazone
- Adults: starting dose of sulfinpyrazone is 100 mg or 200 mg a day (one-half of a 100-mg tablet two times a day, one 100-mg tablet one or two times a day, or one 200-mg capsule or tablet once a day). Then, the dose is usually increased by 100 mg or 200 mg every few days, up to 800 mg a day.
Probenecid (used only to prevent attacks)
- Adults: 250 mg two times a day for about one week, then 500 mg two times a day for a few weeks. After this, the dose will depend on the amount of uric acid in your blood or urine.
Adverse Drug Reactions
NSAIDs
- Dyspepsia,
- Peptic Ulcer Disease,
- Gastrointestinal haemorrhage, renal insufficiency, hepatotoxicity, heart failure (especially elderly persons)
Allopurinol
- Elevated liver enzymes,
- Allopurinol Hypersensitivity Syndrome:
- liver failure, renal failure, eosinophilia, hypersensitivity skin.