Gout: Symptoms, Causes, Treatment, Prevention

Gout: what is it? :

Gout is a disorder of purine metabolism characterized by deposition of uric acid crystal in joints and periarticular tissue. Gout is one of the 3 crystal deposition disorders. Other crystal deposition disorders are ‘pseudo gout’ and ‘calcium hydroxyapatite deposition disorder’.

Types of gout:

Gout is of 2 types.

1. Primary gout (95%)
2. Secondary gout (5%)

Gout is also classified as:

1. Acute gout
2. Chronic gout

Causes of gout:

Primary gout:

Primary gout has no known definite cause. It has some predisposing factors:

1. Hereditary
2. Age: specially between 2^nd and 4^th decade of life
3. Sex: male:female ratio is 15:1
4. Trauma
5. Obesity
6. Alcohol (more lactic acid→ more uric acid→ gout)
7. Hypertension

Secondary gout:

1. Drugs: hydrochlorothiazide, cyclosporine, ethambutol, pyrazinamide etc.
2. Leukemia
3. Polycythemia
4. Lymphoma
5. Psoriasis
6. Starvation
7. Over eating
8. Dehydration
9. Renal failure

Sources of uric acid which is responsible for gout:

Endogenous (70%): from purine metabolism

Exogenous (30%): from purine rich diet such as liver, brain, kidney, heart (in short, all organ meats).

Pathogenesis of gout:

• Disorder of purine metabolism causing hyperuricemia.
• Deposition of sodium urate crystals in articular and periarticular structures.
• Crystals produce inflammatory reaction.
• There is erosion of bones and cartilages.
• Pannus (Granulation tissue) formation within joint cavity.
• Fibrous ankylosis of joint.
• Irregularity of articular surface may lead to secondary osteoarthritis.

Symptoms of gout:

1. Sudden onset of severe sharp pain in affected joint. Usually gout appears first in metacarpophalangeal joint of great toe. Pain lasts for hours to weeks.
2. Pain is so severe that patient may not allow even to touch the affected area.
3. Tophus formation in various areas of body. Size of tophi may be 2-20 cm.
4. Stiffness of joint.

Fig: tophus

Fig: ulcerated tophus

Investigations for gout:

1. TC, DC, ESR (increases)
2. Blood uric acid (increased)
3. Arthrocentesis and examination of joint fluid under polarized microscope to see urate crystals which are small rod or pin shaped.
4. X ray: at first stage of gout, there is no findings, later, joint space is seen reduced, erosion of bone and cartilage is seen (as in osteoarthritis)

Fig: gout x ray

Treatment of gout:

General treatment of gout:

1. Bed rest
2. Immobilization
3. Purine diet restriction
4. Alcohol restriction
5. Plenty of water intake

Drugs for gout:

Acute gout:

1. Colchicine
2. Phenylebutazone
3. Oxyphenbutazone
4. Indomethacin
5. Intra articular steroid injection

Chronic gout:

1. Colchicine
2. Allopurinol
3. High dose aspirin (5-6 gm/day)
4. Probenecid
5. Sulphin pyrazone
6. Febuxostate

Operative treatment for gout:

1. Excision of gout lesion
2. Arthrodesis in functional position

Prevention of gout:

1. Plenty water intake
2. Less taking purine diet
3. Control blood pressure
4. Control obesity
5. Avoid alcohol
6. Diuretics should be used stealthily
7. Kidney care