Tuberculin conversion and abnormal chest radiograph in an infant.

A 15 month old girl, who had not received bacille Calmette-Guérin (BCG) vaccine, and who had no known exposure to tuberculosis, was hospitalized because of Salmonella enteritis. The child also suffered from persistent coughing. The primary routine Mantoux skin test with 100 tuberculin units (TU) was remarkably positive (20 mm induration) for the first time, so that tuberculin conversion was defined. Therefore, the child was presented to our out-patient department and a radiographic examination was performed (fig. 1). Breathing and percussion sound were reduced in the basal area of the right lung. The child had no fever and her clinical status was normal. There were no indications of foreign body aspiration. The child was admitted for further examination and bronchoscopy. The laboratory findings were: erythrocyte sedimentation rate (ESR) 8/30 mm·h-1; C-reactive protein (CRP) below the detection limit. The blood count showed a slight leucocytosis of 15.8×109 cells·L-1. Immunoglobulins in serum were normal. A Mantoux test with 1 TU showed a positive reaction of 8 mm induration. Three samples of gastric juice were microscopically negative for mycobacteria. Bronchoscopy showed total occlusion of the bronchus intermedius due to perforation of lymph nodes. There was no microscopic evidence of mycobacteria in either the bronchial secretion or lymph node material. The bronchus intermedius was recanalized during the same session. Due to the tuberculin conversion and abnormal radiographic image, as well as the bronchoscopic findings (macroscopic: necrotic lymph node material; histological: epithelioid cell granulomatosis), a primary tuberculosis was initially diagnosed, despite lack of microscopic evidence of tuberculosis bacteria. Combined antituberculotic chemotherapy (isoniazid, rifampin, pyrazinamide) was initiated, which was continued after discharge. Although there were no clinical symptoms, findings of a control radiographic examination 6 weeks later became worse.