Mycoplasma pneumoniae Infection Mimicking Pediatric Tuberculosis: A Case Report

To the Editors: Tuberculosis (TB) remains a significant public health concern in children, particularly in endemic regions. However, diagnosis can be challenging due to other respiratory infections that present with similar clinical and radiological features. Here, we report the case of a 13-year-old boy who was initially hospitalized with a presumptive diagnosis of active pulmonary TB but was ultimately diagnosed with Mycoplasma pneumoniae infection based on further investigation. A previously healthy 13-year-old boy presented to the pediatric outpatient clinic with a 2-week history of fever, cough, loss of appetite, weight loss and night sweats. His immunizations were up to date for his age. Family history revealed that his grandfather had been diagnosed with TB 19 years prior. The patient exhibited no respiratory distress and did not require supplemental oxygen. On physical examination, rhonchi were heard bilaterally. Chest radiograph showed hilar fullness and increased bronchovascular markings. Due to increased parenchymal density in the mid-zones, the radiologist recommended further evaluation with computed tomography. High-resolution computed tomography revealed consolidation in the basal regions of both lungs and miliary-type nodular infiltrates—findings suggestive of active pulmonary TB (Fig. 1).FIGURE 1.: High-resolution computed tomography images of the patient. Axial, coronal and sagittal high-resolution computed tomography images of the chest show bilateral patchy ground-glass opacities (yellow arrows) predominantly in the posterior basal segments of the lower lobes. Diffuse micronodular infiltrates are present throughout both lungs, suggestive of a miliary pattern.The patient was admitted to the pediatric infectious diseases ward with a presumptive diagnosis of pulmonary TB, and respiratory isolation precautions were implemented. A tuberculin skin test was performed. As the patient was unable to expectorate sputum, early morning gastric aspirate samples were collected over 3 consecutive days. TB polymerase chain reaction (PCR) and acid-fast bacilli staining of these samples were negative. A sample was also sent for respiratory multiplex PCR testing. The tuberculin skin test result was 0 mm. Despite ongoing fever, the respiratory multiplex PCR returned positive for M. pneumoniae. Accordingly, oral azithromycin therapy was initiated (10 mg/kg on day 1, followed by 5 mg/kg/day for the next 4 days). The patient showed marked clinical and radiological improvement with azithromycin. As all tests for TB were negative, he was discharged with a plan for outpatient follow-up. Written informed consent was obtained from the parents of the patient. In children, TB should be considered in cases presenting with weight loss, night sweats and persistent cough.1,2 However, other pathogens with similar clinical presentations should be included in the differential diagnosis. M. pneumoniae is a common cause of community-acquired pneumonia in school-aged children and typically follows a subacute course.3,4 In this case, it presented with symptoms and radiologic findings mimicking TB. This underscores the risk of diagnostic error when relying solely on imaging. In pediatric patients with a preliminary diagnosis of TB but without microbiological confirmation, atypical pathogens such as M. pneumoniae should be considered. A comprehensive and systematic diagnostic approach is essential to avoid unnecessary isolation, inappropriate treatment and diagnostic delays.