What is the best next step in managing an 11-year-old girl with polyarticular juvenile idiopathic arthritis (JIA) and a recent onset of severe right shoulder pain, fever, and limited mobility, with synovial fluid analysis revealing a high leukocyte count with predominance of polymorphonuclear cells?

From the Guidelines

The best next step in management for this patient is to begin antibiotic therapy. This 11-year-old girl presents with signs and symptoms highly suggestive of septic arthritis of the right shoulder, which requires immediate antibiotic treatment. The high fever, severe pain that wakes her at night, inability to move the shoulder, warm overlying skin, and most importantly, the synovial fluid analysis showing 55,000 leukocytes/mm³ with 80% polymorphonuclear cells strongly indicate an infectious process rather than a flare of her juvenile idiopathic arthritis 1. Empiric intravenous antibiotics should be started immediately, typically with coverage for Staphylococcus aureus and streptococci, such as cefazolin or oxacillin/nafcillin, pending culture results. Children with autoimmune conditions on immunosuppressive medications like methotrexate are at increased risk for infections, including septic arthritis. Delaying antibiotic therapy could lead to joint destruction, osteomyelitis, or systemic infection.

Some key points to consider in the management of this patient include:

• The presence of a high fever and severe pain, which are indicative of an infectious process 1
• The results of the synovial fluid analysis, which show a high leukocyte count with a predominance of polymorphonuclear cells, consistent with septic arthritis 1
• The importance of prompt antibiotic therapy in the treatment of septic arthritis, as delayed treatment can lead to serious complications 1
• The need to cover for common pathogens such as Staphylococcus aureus and streptococci with empiric antibiotic therapy 1

The other management options, such as adding a biologic disease-modifying antirheumatic drug, administering intra-articular glucocorticoids, increasing the methotrexate dose, or recommending nonsteroidal anti-inflammatory drugs and rest, would be inappropriate as they would not address the infectious process and could potentially worsen the patient's condition by further suppressing the immune system. The guidelines for the treatment of juvenile idiopathic arthritis, as outlined in the 2019 American College of Rheumatology guideline, do not apply in this case, as the patient's presentation is consistent with septic arthritis rather than a flare of her underlying disease 1.

From the FDA Drug Label

Atrophy of subcutaneous fat may occur if the injection is not properly given. A single local injection of triamcinolone acetonide is frequently sufficient, but several injections may be needed for adequate relief of symptoms. Initial dose: 2. 5 mg to 5 mg for smaller joints and from 5 mg to 15 mg for larger joints, depending on the specific disease entity being treated. The patient has a history of polyarticular juvenile idiopathic arthritis and is currently experiencing a severe exacerbation of shoulder pain with elevated temperature and leukocyte count of 55,000 cells/mm3. The best next step in management would be to Begin antibiotic therapy as the patient's symptoms suggest a possible septic arthritis, which is a medical emergency. Intra-articular glucocorticoids may be considered after the infection has been ruled out or adequately treated. Increasing the methotrexate dose or adding a biologic disease-modifying antirheumatic drug may not be the best next step as they may not address the potential infection. Nonsteroidal anti-inflammatory drugs and rest may not be sufficient to manage the patient's symptoms. 2

From the Research

Patient Presentation and History

• The patient is an 11-year-old girl with a history of polyarticular juvenile idiopathic arthritis, currently taking methotrexate.
• She presents with right shoulder pain, which started 4 days ago after softball practice, and has been worsening despite initial improvement with cold compresses and acetaminophen.
• The patient has a fever of 38.5 C (101.3 F) and significant pain and resistance to movement in the right shoulder.
• Synovial fluid analysis reveals a leukocyte count of 55,000 cells/mm3, with 80% polymorphonuclear cells and 20% lymphocytes.

Diagnosis and Management

• The patient's presentation and synovial fluid analysis are consistent with septic arthritis, a rheumatologic emergency that requires prompt diagnosis and treatment 3, 4.
• The patient's history of juvenile idiopathic arthritis and immunosuppressive medication use (methotrexate) increase her risk for septic arthritis 3.
• Empiric antibiotic therapy should be initiated as soon as possible, given the clinical concern for septic arthritis 3, 5.
• The choice of antibiotic should be based on the likely pathogens and local epidemiology, with consideration for coverage of Staphylococcus aureus, streptococci, and other common causes of septic arthritis 6.

Next Steps in Management

• The best next step in management would be to begin antibiotic therapy, given the high suspicion for septic arthritis and the potential for significant morbidity and mortality with delayed treatment 3, 5.
• Option C, Begin antibiotic therapy, is the most appropriate choice, as it addresses the urgent need for treatment of septic arthritis.
• Options A, B, D, and E do not directly address the need for empiric antibiotic therapy in the setting of suspected septic arthritis.