A two years old girl was admitted to our division because of fever, cough and dyspnea. The girl had arrived in Italy from Romania just seven days before when she reached his family living in a nomad camp. The first chest x-ray showed right pleural effusion and right middle and lower lobes consolidation. Antibiotic therapy was started without any clinical benefit. Therefore, a tuberculin skin test (TST) was performed with a markedly positive result after 72 hours. Because of sudden worsening dyspnea, emergency chest computed tomography (CT) was carried out and the presence of relevant pleural effusion all around the right lung, with parenchymal lung consolidation and paratracheal, subcarinal and hilar lymphadenopathy was highlighted (Figure 1). Interferon-gamma releasing assay (IGRA) tests firstly gave an indeterminate result but, repeated a week later, it gave a positive result. An evacuative thoracentesis was made and polymerase-chain-reaction (PCR) resulted positive for Mycobacterium tuberculosis (Mtb). An anti-TB therapy with isoniazid (INH), rifampicin (RMP) and pyrazinamide (PZD) was begun with rapid improvement of the girl's clinical conditions. All the microscopic, nucleic acid amplification techniques and cultural exams carried out on gastric lavages and urine gave negative results for Mtb. The last chest x-ray, carried out after one month of therapy, showed an almost complete resolution of the pleural effusion, of the parenchymal disventilation areas and of the lymphadenopathy.
About 75% of childhood TB disease is pulmonary and up to a third of all pediatric pulmonary TB cases may be complicated by pleural effusion, which may also be found without any significant concomitant parenchymal disease. Pulmonary TB commonly presents with a persistent (>21 days) and unremitting cough, with or without fever, not improving despite appropriate first line antibiotic treatment.
The diagnosis of TB is not usually considered in a febrile child unless the fever is persistent (> 7 days) or other clinical features suggestive of TB are present. Positive family history for travelling or origins from TB endemic countries and overcrowded living environments should induce the diagnostic suspicion of TB.
The examination of pleural fluid is important to establish the diagnosis of TB pleuropneumonia. Nevertheless, cultures of the fluid are positive only in a low number of cases and it takes them a long time to get the result. Nowadays PCR is an helpful diagnostic tool for early diagnosis and it has good sensitivity and specificity.
During the last years, IGRA was introduced into clinical practice as a diagnostic tool with high specificity for the diagnosis of Mtb infection, even though it is not able (as TST) to discriminate between active TB disease and latent TB infection. During childhood, due to the lymphocytic anergy secondary to infections, IGRA tests may initially give indeterminate results. As a consequence, in case of strong suspicion of TB, IGRA should be repeated even in case of undeterminate results.
Chest computed tomography revealed the presence of relevant pleural effusion all around the right lung, with parenchymal lung consolidation and paratracheal, subcranial and hilar lymphadenopathy.