Are there different types of gout?
Gout develops over many years as a consequence of increased uric acid levels (hyperuricaemia). Doctors currently describe the disease in four different stages:
Acute gout attack
Periods between two recurrent attacks of gout without symptoms
The chronic form of gout is called "tophaceous gout". In this stage, the body develops lumps of uric acid crystals (tophi) in the soft tissue areas.
Podagra is an acute gout attack in the big toe joint. The most commonly affected joint in about 50 % of cases is the metatarsophalangeal joint, which is located at the base of the big toe.
Gout is a type of arthritis accompanied by hyperuricaemia. Uric acid levels higher than 6 mg/dl (360 mmol/l) create the risk of uric acid crystals forming and depositing in tissues.
This can cause the acute inﬂammation that characterises acute gouty arthritic attacks. A second acute gout attack is experienced within one year of the first by 40 to 60 % of individuals. Increasingly frequent, prolonged and severe attacks occur over the years in the majority of gout patients.
"Tophi" is derived from the Latin word "tophus", meaning stone. Tophi are build-ups of uric acid crystals found in soft tissue areas in chronic gout. They can form in joints, cartilage, bones and other places in the body. Sometimes, they are able to penetrate into the skin. They appear as white-yellow chalky nodules.
The chronic form of gout is called "tophaceous gout". At this stage, the body develops lumps of uric acid crystals (tophi) in the soft tissue areas.
"Tophaceous lesions" develop in many untreated gout patients and can cause a chronic arthritis (gouty arthropathy) with destruction and deformation of joints and similar damage to bones, tendons, bursae (the fluid-filled cushions between bone and soft tissue), skin and even solid organs.
Recurrent gout attacks, chronic arthropathy, and tophi are in many instances directly responsible for chronic pain, impairment of work and day-to-day activities and reduced quality of life. Substantial improvement and/or reversal of these symptoms is seen when a long-term reduction and maintenance of uric acid levels below 6 mg/dl, or 360 µmol/l, is achieved through uric acid-lowering therapy.
Uric acid levels above 6 mg/dl, or 360 µmol/l, may lead to the formation of uric acid crystals; these crystals can build up in tissues, joints or the kidneys and lead to rheumatic inflammation, swelling and severe pain, which occurs in flares.
Having high concentrations of uric acid in the blood is known as "hyperuricaemia". If no symptoms or signs of uric acid crystal deposits such as gout or uric acid kidney disease occur, this is called "asymptomatic hyperuricaemia".