Juvenile rheumatoid arthritis

Juvenile rheumatoid arthritis (JRA) is arthritis of unknown cause, lasting more than 6 weeks, developing in children under 16 years of age with the exclusion of other joint pathologies.

Depending on the type of classification, the disease has the following names: juvenile arthritis (ICD-10), juvenile idiopathic arthritis (ILAR), juvenile chronic arthritis (EULAR), juvenile rheumatoid arthritis (ACR).

ICD-10 code

• M08. Juvenile arthritis.
• M08.0. Juvenile rheumatoid arthritis (seropositive or seronegative).
• M08.1. Juvenile ankylosing spondylitis.
• M08.2. Juvenile arthritis with systemic onset.
• M08.3. Juvenile polyarthritis (seronegative).
• M08.4. Pauciarticular juvenile arthritis.
• M08.8. Other juvenile arthritis.
• M08.9. Juvenile arthritis, unspecified.

Epidemiology of juvenile chronic arthritis

Juvenile rheumatoid arthritis is one of the most common and most disabling rheumatic diseases that occurs in children. The incidence of juvenile rheumatoid arthritis is from 2 to 16 people per 100,000 children under 16 years of age. The prevalence of juvenile rheumatoid arthritis in different countries is from 0.05 to 0.6%. Girls are more often affected by rheumatoid arthritis. The mortality rate is 0.5-1%.

Adolescents have a very unfavorable situation with rheumatoid arthritis, its prevalence is 116.4 per 100,000 (in children under 14 years old - 45.8 per 100,000), primary incidence is 28.3 per 100,000 (in children under 14 years old - 12.6 per 100,000).

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Causes of Juvenile Chronic Arthritis

Juvenile rheumatoid arthritis was first described at the end of the last century by two famous pediatricians: the Englishman Still and the Frenchman Shaffar. Over the following decades, this disease was referred to in the literature as Still-Shaffar disease.

The symptom complex of the disease included: symmetrical joint damage, formation of deformations, contractures and ankylosis in them; development of anemia, enlargement of the lymph nodes, liver and spleen, sometimes the presence of febrile fever and pericarditis. Subsequently, in the 30-40s of the last century, numerous observations and descriptions of Still's syndrome revealed much in common between rheumatoid arthritis in adults and in children, both in clinical manifestations and in the nature of the course of the disease. However, rheumatoid arthritis in children still differed from the disease with the same name in adults. In this regard, in 1946, two American researchers Koss and Boots proposed the term "juvenile (adolescent) rheumatoid arthritis". The nosological distinctness of juvenile rheumatoid arthritis and rheumatoid arthritis in adults was subsequently confirmed by immunogenetic studies.

What causes juvenile rheumatoid arthritis?

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Pathogenesis of juvenile chronic arthritis

The pathogenesis of juvenile rheumatoid arthritis has been intensively studied in recent years. The development of the disease is based on the activation of both cellular and humoral immunity.

Pathogenesis of juvenile chronic arthritis

Symptoms of Juvenile Chronic Arthritis

The main clinical manifestation of the disease is arthritis. Pathological changes in the joint are characterized by pain, swelling, deformations and limitation of movement, increased temperature of the skin over the joints. In children, large and medium joints are most often affected, in particular, the knee, ankle, wrist, elbow, hip, and less often - small joints of the hand. Typical for juvenile rheumatoid arthritis is damage to the cervical spine and temporomandibular joints, which leads to underdevelopment of the lower, and in some cases the upper jaw and the formation of the so-called "bird jaw".

Symptoms of Juvenile Chronic Arthritis

Classification of juvenile chronic arthritis

Three classifications of the disease are used: the American College of Rheumatology (ACR) classification of juvenile rheumatoid arthritis, the European League Against Rheumatism (EULAR) classification of juvenile chronic arthritis, and the International League of Rheumatology Associations (ILAR) classification of juvenile idiopathic arthritis.

Classification of juvenile chronic arthritis

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Diagnosis of juvenile chronic arthritis

In the systemic variant of juvenile rheumatoid arthritis, leukocytosis (up to 30-50 thousand leukocytes) with a neutrophilic shift to the left (up to 25-30% of band leukocytes, sometimes up to myelocytes), an increase in ESR to 50-80 mm/h, hypochromic anemia, thrombocytosis, an increase in the concentration of C-reactive protein, IgM and IgG in the blood serum are often detected.

Diagnosis of juvenile chronic arthritis

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Treatment goals for juvenile chronic arthritis

• Suppression of inflammatory and immunological activity of the process.
• Relief of systemic manifestations and articular syndrome.
• Preservation of the functional capacity of joints.
• Prevention or slowing down of joint destruction and patient disability.
• Achieving remission.
• Improving the quality of life of patients.
• Minimizing side effects of therapy.

Treatment of juvenile chronic arthritis

Prevention of juvenile chronic arthritis

Since the etiology of juvenile rheumatoid arthritis is unknown, primary prevention is not performed.

Forecast

In the systemic variant of juvenile rheumatoid arthritis, the prognosis is favorable in 40-50% of children, and remission may occur lasting from several months to several years. However, an exacerbation of the disease may develop years after a stable remission. In 1/3 of patients, the disease continuously recurs. The most unfavorable prognosis is in children with persistent fever, thrombocytosis, and long-term corticosteroid therapy. Severe destructive arthritis develops in 50% of patients, amyloidosis is observed in adulthood in 20%, and severe functional insufficiency is observed in 65%.

All children with early onset of polyarticular seronegative juvenile arthritis have an unfavorable prognosis. Adolescents with seropositive polyarthritis have a high risk of developing severe destructive arthritis and disability due to the state of the musculoskeletal system.

In 40% of patients with early-onset oligoarthritis, destructive symmetrical polyarthritis develops. In patients with late onset, the disease may transform into ankylosing spondylitis. In 15% of patients with uveitis, blindness may develop.

An increase in the level of C-reactive protein, IgA, IgM, IgG is a reliable sign of an unfavorable prognosis for the development of joint destruction and secondary amyloidosis.

Mortality in juvenile arthritis is low. Most deaths are associated with the development of amyloidosis or infectious complications in patients with the systemic variant of juvenile rheumatoid arthritis, often resulting from long-term glucocorticoid therapy. In secondary amyloidosis, the prognosis is determined by the possibility and success of treating the underlying disease.

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