Definition
Gouty arthritis is a disease characterized by metabolic dysfunction, which causes a deposition of uric acid crystals in the joints. At the base of this condition, in particular, there is an alteration of the purine turnover, which leads to the production of excessive amounts of urates (salts of uric acid) and to an increase in their acid (hyperuricemia) in the blood. This results in an acute, recurrent or chronic (inflammatory arthritis) joint inflammatory attack.
The increased production of urates can occur in situations where there is a high index of proliferation and cell death (eg psoriasis, haemolytic anemia, tumor lysis syndrome or leukemia). An increase in the serum level of uric acid can also be induced by some drugs (including diuretics, salicylates and cyclosporine used in transplanted patients), cytotoxic chemotherapy and radiotherapy.
Gouty arthritis can also affect individuals who produce a normal amount of urates, but have difficulty eliminating them due to a specific defect in renal function. The reduced excretion can be hereditary or develop in the presence of pathologies that reduce the glomerular filtration rate.
Furthermore, uric acid levels can be elevated due to an increased intake of purine-rich foods (eg liver, anchovies, asparagus, herring, meat sauces and broths).
Gout is rare in young age, but it is more serious in those who develop the disease before the age of 30.
Uric acid precipitates in the form of needle-like crystals of monosodium urate, which are deposited in the extracellular site in avascular tissues (eg cartilage) or poorly vascularized (eg tendons, tendon sheaths, ligaments, bursa walls) and in the skin around the peripheral joints. In severe chronic forms, the crystals can deposit in the larger central joints and in the parenchyma of organs such as the kidneys.
The attacks of acute gouty arthritis can be triggered by trauma, physical stress (eg pneumonia or other infections), surgery, use of thiazide diuretics or drugs with uricosuric activity (eg allopurinol) or excessive consumption of purine-rich foods or alcohol.
Most common symptoms and signs *
- Ankylosis
- Asthenia
- Increase in the ESR
- Kidney stones
- Knee pain
- Foot pain
- Heel pain
- Hand and wrist pain
- Shoulder pain
- Articolar pains
- Legs tired, heavy legs
- Joint swelling
- Increased blood urea
- Hyperuricemia
- Metatarsalgia
- Swollen and tired feet
- podagra
- Rheumatism
- Joint stiffness
- Articular noises
- Tofi
- Bone swelling
Further indications
In most cases, the initial clinical manifestation of uric acid crystal deposition in the joint tissues is represented by a sudden onset inflammation that induces very intense (often nocturnal) painful attacks. At the level of the affected joint, gouty arthritis also involves swelling, while the overlying skin can become tense, warm, shiny and of a purple red color.
Acute arthritis is initially monoarticular and often the first site to be involved is the metatarsofalangea of the big toe (podagra), but also the instep, ankle, knee, wrist and elbow are frequent debut sites. The pain becomes progressively more intense, generally within a few hours, and is often intolerable.
Sometimes fever, tachycardia, chills and malaise appear. Around the deposits of uric acid crystals an intra and extrarticular granulomatous inflammatory reaction (tophi) is formed, which can limit movement and cause deformity (chronic gouty arthritis).
If left untreated, the inflammation remains for several days or weeks before resolving. After a first episode of gouty arthritis, if the level of uric acid in the blood is not lowered, successive attacks are frequent in the same or in other joints. Chronic gouty arthritis can cause pain, deformity and limitation of joint motility. During the course of the disease, inflammation can develop in some joints and subside in others.
Furthermore, at the acid pH of urine, the urine precipitates rapidly in the form of small crystals of flattened or sometimes irregular shape, which can aggregate to form grains or kidney stones, which may predispose to obstructive uropathy.
It should also be considered that in patients with chronic gouty arthritis, there is a higher cardiovascular risk.
Diagnosis is based on physical examination, detection of uricemia and identification of crystals in synovial fluid following an arthrocentesis.
The treatment of acute attacks of gouty arthritis consists of the use of anti-inflammatory drugs. Attack frequency can be reduced by adopting dietary measures, regular use of NSAIDs and / or colchicine and treating hyperuricemia with allopurinol or uricosuric drugs.
