Crystal-induced arthritis

Definition

Crystal-induced arthritis is a group of diseases in which joint inflammation occurs due to the deposition of crystals of various substances. The most common subtype of this disease is gout arthritis, so it will be discussed mostly in this article.

Acute gout arthritis is an inflammation of the joint due to the accumulation of sodium monourate crystals in the periarticular tissues and their subsequent release under the influence of provoking factors. Most often, it affects the I metatarsophalangeal joint. It is characterized by sharp pain, local swelling and hyperemia, fever, and general hyperthermia. After a few days, the symptoms disappear, but subsequently, new attacks are observed with the transition of gout into a chronic form and diagnosed based on complaints, anamnesis, data from physical examination, and laboratory and hardware techniques. Treatment includes NSAIDs, means to correct uric acid metabolism, and corticosteroids.

General information

Acute gout arthritis is the most common type in men over 40. It is the second stage of gout and develops after asymptomatic hyperuricemia. The peak of morbidity in men falls at 40-50 years and in women – at 60 or more years. Pathology is rarely detected in men under 30 years of age and women who have not reached the age of menopause. Among patients up to 50 years of age, there is a 6-7-fold predominance of men; afterwards, the difference in sex distribution gradually decreases.

Causes

Gout arthritis is always formed against the background of previous persistent hyperuricemia. A uric acid level of more than 420 µmol/L is considered critical. In women, crystals can be deposited as early as 360 μmol / l. The risk factor is an increase in the amount of uric acid and its sharp fluctuations. Increased urate content is promoted by:

• Irrational diet. Fish, red meat, and products with a lot of fructose are considered “dangerous.”
• Overweight. Gout often develops in obese people. It often occurs after a sudden weight gain.
• Alcohol abuse. Along with obesity, it is one of the two most significant triggering factors. The use of both hard liquor and beer is important.
• Medication intake. Hyperuricemia occurs more often when taking diuretics, cyclosporine, beta-blockers, and low-dose aspirin.
• Increased purine metabolism is observed in hemoglobinopathies, chronic hemolytic anemia, thalassemia, secondary polycythemia, lympho- and myeloproliferative diseases, and psoriasis.
• Increased production of purines. Identified in Lesch-Nyhan syndrome, glucose-6-phosphate dehydrogenase deficiency.

Risk factors

Traumatic injuries, dehydration, blood loss, alcohol consumption, and food with a high purine content (meat, sardines, shellfish) can provoke an attack of acute arthritis on the background of hyperuricemia. Gout attacks develop against acute infectious diseases, medications (nicotinic acid, aspirin, vitamin B12, allopurinol, diuretics), and radiation therapy. Sometimes, the cause is high physical activity. Symptoms can also appear 3-5 days after various surgical operations.

Classification

Gout can be primary or secondary (symptomatic). The primary form is based on the increased production of uric acid or its insufficient excretion through the kidneys. Symptomatic variant develops when taking medications, kidney pathologies, hereditary enzyme defects, and myeloproliferative diseases.

The number of joints involved estimates the prevalence of the acute process:

• one small;
• 1-2 medium to large;
• three or more large or four or more medium to large, or a regional lesion (polyarticular gout).

Symptoms of gout arthritis

The distal joints of the legs are affected in the absolute majority of patients at the first attacks of gout. The first place in prevalence is occupied by the one metatarsophalangeal joint (more than half of the total cases). Other parts of the foot, knee, ankle, elbow, wrist joint, and hand joints may be involved. Lesions of large joints never develop in the debut but may be observed in subsequent exacerbations.

The localization of arthritis is largely determined by the age and gender of the patient. Men more often suffer from inflammation of the thumb. In women at the early stage of gout, as a rule, poly- or oligoarthritis with involvement of the distal parts of the hands occurs. In elderly patients, polyarticular lesions of the upper extremities with rapid formation of tophi are predominantly detected.

Function is significantly impaired, and support becomes impossible. There is an increase in body temperature, fever, weakness, and chills. Some patients develop tenosynovitis and bursitis. Even without treatment, the symptoms completely disappear after a few days. Sometimes, acute gout arthritis proceeds relatively easily; the manifestations are self-corrected before the specified time. Intervals between attacks vary from a few days to several years. In 62% of patients, a recurrent attack develops within one year.

Diagnosis

A rheumatologist performs the examination. During the anamnesis collection, the specialist discovers the complaints and the history of the disease. An important role is played by identifying risk factors: metabolic syndrome (obesity, increased BP, characteristic metabolic disorders) and taking certain drugs. It is essential to the presence of renal pathologies, alcohol abuse, and the propensity to consume certain products.

The rapid progression of symptoms, intense pain, erythema, typical localization, and the presence of similar attacks in the anamnesis testify in favor of the gout nature of arthritis. As part of the physical examination, assess the appearance and function of the joint and examine the possible locations of the tophi: elbows, first toes, and ears. Additional examination includes:

• Determination of uric acid. The indicator is detected in the blood serum. The presence of hyperuricemia is not a basis for diagnosis but indicates an increased likelihood of gout. When evaluating the results, it is taken into account that during the attack period, the content of uric acid may be normal. Further studies in dynamics are recommended.
• Determination of urate is the “gold standard” for the diagnosis of gout. Polarization microscopy examines synovial fluid obtained during joint puncture or the contents of tophus taken by biopsy. The technique has almost 100% specificity, and crystals are detected in 70% of cases.
• Other laboratory tests. The general blood test reveals increased ESR, leukocytosis, and neutrophilosis. Biochemical examination of blood confirms an increase in C-reactive protein. It is obligatory to determine ALT, AST, creatinine, and lipid profile. 
• Ultrasound of the joints. The method is informative not only in the development of acute arthritis but also before the first gout attack (at the asymptomatic stage). It is essential when it is impossible to examine synovial fluid. 
• Radiography of the joints. At the stage of acute arthritis, to confirm the diagnosis is uninformative, changes in the images appear only 7-10 years after the manifestation of gout. Radiographs are used to exclude traumatic injuries and other joint diseases.

Treatment of acute gout arthritis

The basis of therapy is medications of systemic and local action. Medicines of the following groups are used:

• Nonsteroidal anti-inflammatory. Reduce pain syndrome and reduce the severity of inflammation. Maximum therapeutic doses of drugs with a short half-life are preferred.
• Affecting uric acid metabolism. It is optimal to prescribe from the first hour of the attack. The later the treatment starts, the less pronounced the effect. Treatment is continued until the symptoms are relieved. In kidney disease, they are used with caution.
• Corticosteroids. They are used orally, as parenteral administration may cause a “ricochet” syndrome. In oligo- and monoarthritis, they are injected into the joint or periarticular tissues on the first day of the disease.
• Genetically engineered biological drugs. Interleukin-1 antagonists are indicated in the absence of effects from other methods. They are not recommended in case of suspected septic arthritis or the presence of concomitant infectious diseases.
• Surgical treatment. In rare cases surgical treatment can become a good option for relieving the disease’s burden. In that case, foot arthrodesis, small joints replacement or just an arthrocentesis can be performed.

Physiotherapeutic procedures are contraindicated in the acute condition because they do not provide the desired result and may worsen the condition.

All these treatment options are available in more than 980 hospitals worldwide (https://doctor.global/results/diseases/crystal-induced-arthritis). For example, Arthrocentesis can be done in 50 clinics across Germany for an approximate price of $1,4K (https://doctor.global/results/europe/germany/all-cities/all-specializations/procedures/arthrocentesis). 

Prognosis

The attack usually ends after 7-10 days. Since acute gout arthritis is a manifestation of an existing disease—gout—a complete cure is impossible, but with adequate therapy and compliance with medical recommendations, the prognosis is favorable. Unfavorable prognostic factors are considered to be young age, the presence of progressive kidney disease, and severe concomitant pathologies.

Prevention

The probability of new gout attacks is reduced by following a special diet, avoiding alcohol, normalization of body weight, treatment of provoking and concomitant diseases. If indicated, patients are prescribed hypouricemic and uricosuric drugs.