[Clinical features of children with post-primary tuberculosis]

Objective: The aim of this study was to summarize the clinical and imaging characteristics of post-primary tuberculosis in children, so as to improve the early identification and diagnosis of post-primary tuberculosis. Methods: This was a retrospective study which enrolled children who were admitted to the Department No.2 of Respiratory Medicine, Beijing Children's Hospital Affiliated to Capital Medical University between January 2015 to December 2020 and with a diagnosis of post-primary tuberculosis. Results: A total of 30 patients were enrolled, including 10 males and 20 females. The age on admission were 13.0 (12.0, 13.3) years. Their common symptoms were cough and fever, there were 26 cases (87%) with cough and 23 cases (77%) with fever, but only 4 cases (13%) had other toxic symptoms (night sweat, weakness or weight loss) of tuberculosis other than fever. Blood examination showed that the white blood cell count was (10±3)×10⁹/L, accompanied by elevated proportion of neutrophils (0.69±0.11) and increased level of C-reactive protein (31 (15,81) mg/L). The common radiographic findings of CT were nodular or mass shadow with cavitation (19 cases (63%)), consolidation (13 cases (43%)), bronchogenic spread (12 cases (40%)), hilar or mediastinal lymphadenopathy (5 cases (17%)) in this cohort. The affected locations included the right upper lobe (21 cases (70%)), the left lower lobe (17 cases (57%)) and the right lower lobe (15 cases (50%)). Acid-fast bacillus smears and mycobacterial cultures were attempted for all cases, resulting in 33% (10/30) with smear positivity and 50% (15/30) with culture positivity. Conclusions: Post-primary tuberculosis in children has no specific clinical manifestations. Imaging of chest CT is mainly manifested as nodular shadow with cavitation, consolidation or bronchogenic spread. Accurate identification of post-primary tuberculosis is crucial for preventing the spread and early treatment of tuberculosis.