Tuberculosis manifesting with significant peripheral eosinophilia: A case report and review of literature

KEY CLINICAL MESSAGE: Peripheral eosinophilia is a rare but potential sign of TB infection. Physicians should assess patients for TB, especially if they display related symptoms or risk factors, and consider TB as a differential diagnosis, especially in idiopathic cases. ABSTRACT: Millions of new tuberculosis (TB) cases are reported annually. Peripheral eosinophilia is rare in tuberculosis. We describe a rare case of tuberculosis with a high peripheral eosinophil count. A 9‐year‐old male presented with fever, cough, and respiratory discomfort for a month. The patient's cough did not respond to treatment, along with weight loss and a loss of appetite. A physical examination revealed cervical lymphadenopathy and bilateral lung crepitations. A hematological investigation showed a high eosinophil count of 25,920 cells per cubic millimeter and medical imaging abnormalities consistent with TB. Some malignancies, allergies, and parasitic infections produce peripheral eosinophilia. However, medical literature rarely discusses TB‐induced eosinophilia. Several studies attribute it to mycobacterium antigen hyperreactivity. Eosinophilic release of cytotoxic chemicals may cause tissue damage, and TB patients' eosinophil levels may fluctuate. This case report emphasizes the need to investigate TB in peripheral eosinophilia patients after ruling out other explanations. Our patient benefited from early detection and anti‐TB medication. More studies are required to investigate the causes of TB eosinophilia and its consequences. A detailed medical history and physical examination are essential to diagnose and treat atypical presentations of TB.