Gout is a disease in which body uric acid pool is increased. This will lead to deposition of urate crystals in the joints. Most people with hyperuricemia are asymptomatic. Gout is typically seen in middle aged men. Attacks may be precipitated by excessive food, alcohol, dehydration and diuretic therapy.
Clinical syndrome caused by hyperuricemia
- Acute urate synovitis –acute gout.
- Chronic urate polyarticular gout.
- Chronic tophaceous gout.
- Urate renal stone formation.
Commonest clinical presentation is sudden onset pain in a single joint. Common sites affected are the following. In 50% of cases it involves big toe (metatarsophalangeal joint) as shown in figure.
Podagra. Acute gout with swelling and erythema
Other sites affected are
- Ankle
- Midfoot
- Knee
- Small joints of hands
- Wrist
- Elbow
Large joints of limbs and axial skeleton (spinal joints) are rarely affected.
Acute gout
Characteristic features of pain in acute gout are given below
- Sudden onset of pain, which reach maximum severity in 2 to 6 hours, it may wake up the patient in early morning.
- Patients describe the pain as very severe and ‘worst pain ever’.
- On touching the area severe tenderness occur, patient cannot even wear a sock or let bedding rest on the joint.
- There can be marked swelling with overlying skin become red and shiny.
- The disease is self-limiting, pain resolves over 5 to 14 days, with complete resolution.
- Once the attack subsides, pruritus (itching) and desquamation of skin is seen.
- Along with the above features there can be fever, malaise and confusion particularly if large joints are affected.
- Some patients experience only milder attack. More than one joint may be affected. Cluster attack can occur ,in such case other joint is affected after a few days. But polyarticular involvement is unusual.
Chronic gout
Chronic pain and damage to joints occur which may lead to severe disability and functional impairment. If the hyperuricemia is uncontrolled repeated attack can occur and progress to chronic gout.
Tophus with white monosodium urate monohydrate
Chronic poly articular gout is rare, it is seen in elderly on long duration of diuretic therapy and chronic renal failure.
Chronic tophaceous gout - Urate crystal may be deposited in joints and soft tissues to produce tophi, which appear as irregular firm nodule white in colour. Common sites affected are extensor surfaces of fingers, hands, forearm, elbows, Achilles tendons (back of the ankle joint) and the helix of the ear. Tophi may undergo ulceration and infection.