Juvenile rheumatoid disease Bi refers to rheumatoid disease Bi that occurs before the age of 16 and is a relatively common connective tissue disorder. Its main manifestations include prolonged irregular fever, swelling and pain in large, medium, and small joints, which may lead to joint deformities over time. It is often accompanied by enlargement of the liver, spleen, and systemic lymph nodes, anemia, and elevated white blood cell counts. The younger the child, the more pronounced the systemic symptoms tend to be; in older children, joint symptoms are usually more prominent. This condition can occur at any age but is most common between 2–4 years and 8–10 years, with a higher incidence in girls than boys. The prognosis is better than in adults, with approximately 75% of affected children achieving complete recovery.

bubble_chart Clinical Manifestations

1. Systemic type (i.e., Still's disease): More common in young children, accounting for about 20%. It manifests as high fever, rash, and hepatosplenomegaly, lymphadenopathy, etc. These symptoms often appear before joint symptoms.
   1. Fever: Mostly remittent fever, which can reach above 40°C, may be accompanied by shivering, and can last for weeks or even months. It often resolves spontaneously but is prone to recurrence.
   2. Rash: Often accompanied by fever, the rash is polymorphic, scattered, and varies in size, sometimes merging into patches or appearing as annular erythema. The rash is short-lived but prone to recurrence. It is more common on the trunk but can also appear on the limbs, even the palms and soles.
   3. Joint symptoms: Mostly manifest as polyarticular involvement, generally mild, and some cases may have no joint symptoms at all.
   4. Cardiopulmonary lesions: Carditis is the most severe symptom of this type, which may include cardiomegaly and heart failure. Pericarditis is more common than myocarditis, while endocardial membrane involvement is rare. Interstitial pneumonia may be observed in the lungs, with a few cases complicated by pleuritis.
   5. Hepatosplenomegaly and lymphadenopathy: Mostly varying degrees of enlargement. Liver function impairment is more common than hepatomegaly but often improves as the condition alleviates.
2. Polyarticular type: Accounts for about 40%, with manifestations similar to adult-type rheumatoid arthritis.
   1. Systemic symptoms: Mostly mild, including only low-grade fever, lack of strength, loss of appetite, grade I anemia, and grade I hepatosplenomegaly and lymphadenopathy. A few may have subcutaneous nodules near the joints. Rheumatoid factor may be positive.
   2. Joint symptoms: Initially, only 1–2 joints are involved, migratory in the early stages, gradually becoming fixed and symmetrical arthritis. The main characteristic of this type is the involvement of small joints, such as interphalangeal joints, though large joints like the knees, ankles, wrists, elbows, and cervical spine may also be affected.
   This type has a slow onset, and a few cases may eventually lead to joint deformity and stiffness.
3. Monoarticular type: Accounts for about 40%.
   1. Systemic symptoms: Mild, possibly including low-grade fever, lack of strength, grade I anemia, and hepatosplenomegaly and lymphadenopathy.
   2. Joint symptoms: Only a few joints are involved, often just a single joint, mainly affecting large joints like the knees, ankles, and elbows. The joints usually exhibit a chronic inflammatory process or recurrent episodes but rarely lead to restricted joint movement.
   3. Iridocyclitis: A few cases may develop iridocyclitis simultaneously with or after joint involvement, which can lead to blindness and must be prevented and treated early.

bubble_chart Auxiliary Examination

1. During the active phase, a complete blood count often reveals grade I anemia and leukocytosis, particularly in systemic cases where it can be significantly elevated with a left shift.
2. Other active-phase markers include a markedly increased erythrocyte sedimentation rate (ESR), frequently positive C-reactive protein (CRP), and elevated anti-streptolysin O (ASO) levels in approximately half of the cases.
3. Plasma protein electrophoresis shows decreased albumin and increased globulin levels. In the early active phase, α2 and γ globulins are elevated, while in the advanced stage, globulin levels are significantly increased.
4. The positive rate for rheumatoid factor is only about 10–20%, and those who test positive generally have a poorer prognosis.
5. The positivity rate and titer of antinuclear antibodies are not particularly high.
6. X-ray examinations in the early stages may only show soft tissue swelling around the joints. In advanced stages, osteoporosis, joint destruction, narrowing of the joint space, and even semi-dislocation may be observed, though individual variations are considerable.

bubble_chart Treatment Measures

1. During the acute fever phase, patients should rest in bed. As the condition improves, appropriate physical activity should be undertaken. Some cases may require physiotherapy or functional exercises to prevent joint deformities.
2. For patients with severe systemic symptoms or complications such as myocarditis or iridocyclitis, early administration of prednisone is necessary. The initial dose is 1.5–2 mg/kg per day, divided into 3–4 oral doses. As the condition improves and the erythrocyte sedimentation rate normalizes, the dose can be gradually reduced and switched to alternate-day administration or intermittent use. The treatment course lasts 4–6 months or longer.
3. Aspirin is the first-choice nonsteroidal anti-inflammatory drug, with proven efficacy and good tolerability. A higher initial dose of 80–100 mg/kg per day, divided into 3–4 doses taken after meals, may be used. Serum salicylate levels should be monitored to maintain a concentration of 20–30 mg/dl. During treatment, elevated serum aspartate aminotransferase levels may occur but will normalize upon discontinuation. Other drugs, such as indomethacin (0.5–1 mg/kg per dose, 2–3 times daily after meals), should only be considered if aspirin is ineffective or causes toxic reactions.
4. Gold compounds are effective for active arthritis. Gold can reduce new bone erosion. Intramuscular injections of gold sodium thiomalate or aurothioglucose are initiated at 1 mg/kg per week, gradually reduced to 1 mg/kg per month. These are contraindicated in patients with liver, kidney, or blood disorders. Toxic reactions, including cutaneous pruritus, dermatitis, stomatitis, proteinuria, granulocytopenia, thrombocytopenic purpura, and aplastic anemia, warrant discontinuation.
5. Immunosuppressants such as cyclophosphamide, methotrexate, and azathioprine can suppress inflammation in severe cases, enhance the effects of corticosteroids, and reduce corticosteroid dosage.