Acute rheumatic fever mimicking thyroid storm in an adolescent: a case report.

BACKGROUND: Acute rheumatic fever (ARF) is caused by an autoimmune response to throat infection with group A Streptococcus. ARF and its sequel, chronic rheumatic heart disease, remain significant public health problems in many low-income countries. Rapid diagnosis and timely treatment of ARF are essential to avoiding serious adverse outcomes. CASE PRESENTATION: A 16-year-old adolescent with hyperthyroidism and treatment noncompliance presented with symptoms such as fever, difficulty lying flat at night, cough with expectoration, palpitations, and tachypnea. On the basis of the patient’s symptoms, physical signs, and laboratory test results, a preliminary diagnosis of thyroid storm (TS) was made, and hydrocortisone, antithyroid drugs, and anti-infective agents were promptly administered. However, subsequent examinations revealed hemorrhagic pericardial and pleural effusions, indicating that hyperthyroidism complicated by other conditions (including tuberculosis, malignancies, and certain autoimmune diseases) should be considered. Ultimately, the diagnosis of ARF was confirmed on the basis of his dramatic clinical response to hydrocortisone, cardiac inflammatory manifestations, and significantly elevated erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and anti-streptolysin O (ASO) levels. Follow-up revealed that the patient’s rheumatic fever was well controlled and alleviated by treatment. CONCLUSIONS: ARF may have multiple clinical manifestations, but hemorrhagic pericardial and/or pleural effusions are extremely rare. In children and adolescents from developing countries, even in the absence of pharyngitis or tonsillitis, ARF should always be considered when symptoms such as unexplained fever, diaphoresis, palpitations, emaciation and epistaxis are present.