1.What is gout stone Gout stone, also known as gout nodule, is a white crystal precipitated in a part of the body due to excessive elevation of blood uric acid, exceeding its saturation, just like a white deposit will appear at the bottom of a glass of salt water after the amount of salt in the glass exceeds a certain limit. Gout stones can be formed in almost all tissues of gout patients, except for the central nervous system. Some gouty stones cannot be seen with the naked eye, but can be seen as white needle-like crystals under a polarized light microscope. These tiny crystals can trigger the onset of gouty arthritis and can also cause destruction of joint cartilage and bone, fibrosis of surrounding tissues, resulting in chronic joint swelling, pain, stiffness, deformity, and even fracture. Some gout stones are deposited on the surface of the body, such as around the ears and joints, and can be seen by our naked eyes. Some gout stones are also deposited in the kidneys, causing kidney stones and inducing renal colic. Deng Weiming, Department of Rheumatology and Immunology, Second People’s Hospital of Guangdong Province 2. Preferred sites of gout stones Gout nodules on the body surface are found on the extensor side of joints, tendons and the surface of bony prominences. The common site is the external ear, especially the ear whorl (typical) and the opposite ear whorl are common; followed by the first metatarsophalangeal joint of the foot, ankle, fingers, wrist, ulnar hawser, knee capsule and Achilles tendon. 3.Characteristics of gout stone (1)Sesame-egg-sized, yellowish-white nodules protruding from the skin surface. (2) The texture is hard. (3) The surface is thin, and the white paste (uric acid crystals) is discharged after rupture, although it does not heal for a long time, but rarely secondary infection, because uric acid can inhibit bacterial growth. (4) The number varies, generally 1-10. 4.X-ray performance of gout stone Pure uric acid stones, also called soft stones, can be transmitted by X-rays, so they cannot be found in ordinary X-rays. However, pyelogram can confirm the existence of stones; if the stones contain calcium salts, they are hard stones, which can be shown in plain X-rays. We cannot deny the existence of gout stones if no stones are found in plain X-ray film. It is worth noting that 40% of patients with urinary stones can appear before gouty arthritis, even 10 years ahead of time, so patients with urinary stones should be alert to the presence of gout, and blood uric acid can be monitored to clarify the diagnosis. 5, the relationship between gout stone and uric acid salt The increase of uric acid level directly affects the formation of gout stone, the higher the blood uric acid level,
The higher the blood uric acid level, the higher the chance of gout stone. Gout stones can occur in 50% of patients with blood uric acid levels above 535.32umolML. In addition, 20% of patients with gout stones are prone to urinary tract stones. Therefore, it is very important to control the blood uric acid level to reduce the formation of gout stones and reduce the damage to the kidney. 6, the relationship between gout stones and the course of the disease Gout stones mostly occur in patients who have had the disease for about 10 years. The time between the first attack of gout and the formation of gout stone is 4-42 years, with an average of 11.6 years. The longer the duration of the disease, the more gout stones there are. The incidence of gout stones is about 10% for those with <5 years of disease, 55% for those with 5-20 years, and 70% for those with >20 years. The formation of gout stones visible to the naked eye is a sign that the course of gout has become chronic. 7, how to deal with gout stone (1) alkalinization of urine:
Alkalinization of urine is beneficial to the dissolution and excretion of uric acid salts, especially important for the prevention of uric acid kidney stones and gouty nephropathy. This includes eating more alkaline food and rational application of alkaline drugs, but this is often not taken seriously. (2)Treatment of uric acid-lowering drugs:There are indications for uric acid-lowering drug therapy, and it is generally considered that uric acid-lowering drugs should be applied in the following cases: acute gouty arthritis with more than 2-3 episodes per year, with gouty stones, manifestations of kidney damage, or those whose blood uric acid is still significantly elevated by dietary control. (3) Surgery: If the gout stone is not large and does not affect the function of organs, surgery is not necessary because surgical removal of gout stone does not cure the disease, but only in the following cases: gout stone affects the function of joints or compresses nerves; removal of necrotic fingers (toes) due to uric acid erosion or correction of deformed joints; removal of huge gout stone to reduce the burden on the kidneys. Surgery should be performed after normalization of blood uric acid. To prevent surgery-induced acute gouty arthritis, it is best to take non-steroidal anti-inflammatory drugs before and within one week after surgery.