Differential Diagnosis for a 5-year-old Girl with Prolonged Fever
Single Most Likely Diagnosis
- Juvenile Idiopathic Arthritis (JIA): Given the prolonged fever, elevated CRP, and increased white blood cell count with neutrophilia, JIA is a strong consideration. It is a common cause of chronic fever in children, and the absence of a clear infectious etiology supports this diagnosis.
Other Likely Diagnoses
- Infective Endocarditis: Although blood tests for common infections are negative, infective endocarditis can present with prolonged fever and elevated inflammatory markers. The diagnosis requires a high index of suspicion and further evaluation with echocardiography.
- Osteomyelitis or Septic Arthritis: These conditions can cause prolonged fever and elevated white blood cell count. A thorough physical examination and imaging studies (e.g., MRI or bone scan) may be necessary to diagnose these conditions.
- Lymphoma: Although less common, lymphoma can present with prolonged fever, weight loss, and elevated inflammatory markers. Further evaluation with imaging studies and biopsy may be necessary.
Do Not Miss Diagnoses
- Meningitis or Brain Abscess: These conditions can be life-threatening if not promptly diagnosed and treated. Although the presentation may not be typical, a lumbar puncture and imaging studies (e.g., MRI) should be considered to rule out these conditions.
- Sepsis: Sepsis can present with non-specific symptoms, including prolonged fever and elevated inflammatory markers. A thorough evaluation of the child's vital signs, physical examination, and laboratory results is necessary to diagnose sepsis.
- Leukemia: Leukemia can cause prolonged fever, weight loss, and elevated white blood cell count. A bone marrow biopsy may be necessary to diagnose this condition.
Rare Diagnoses
- Kawasaki Disease: Although typically presenting with a characteristic rash and desquamation, Kawasaki disease can cause prolonged fever and elevated inflammatory markers. The diagnosis requires a high index of suspicion and further evaluation with echocardiography.
- Chronic Granulomatous Disease: This rare genetic disorder can cause recurrent infections and prolonged fever. Further evaluation with diagnostic tests (e.g., dihydrorhodamine 123 flow cytometry) may be necessary to diagnose this condition.
- Hyper-IgD Syndrome: This rare genetic disorder can cause recurrent episodes of fever and elevated inflammatory markers. Further evaluation with genetic testing and laboratory studies may be necessary to diagnose this condition.