Lung cavities in an infant: Could it be tuberculosis?

S Save, H Doshi, A Somale 
 Department of Pediatrics, TN Medical College and BYL Nair Hospital, Mumbai Central, Mumbai, Maharashtra, India

Correspondence Address:
S Save
Department of Pediatrics, TN Medical College and BYL Nair Hospital, Mumbai Central, Mumbai, Maharashtra
India

Full Text

Infants present with unusual manifestations of tuberculosis, [1] the diagnosis is often delayed or even missed. A case with pulmonary cavitatory tuberculosis is described here to remind clinicians.

A 90-day-old male child, who had received BCG vaccine at birth presented with low-grade fever for four days; dry, intermittent non-spasmodic cough, associated with post-tussive vomiting for two days and breathlessness for one day. The mother had received a six-month course of anti-tuberculous therapy (ATT) five years back. Her sputum status was not known. On examination, the 4.5-kg infant (length of 59 cm, less than 5 th percentile) was conscious, afebrile and tachypneic (respiratory rate: 56/min) with subcostal and intercostal retractions. Breath sounds were decreased in the right mammary and infra-mammary region. Bronchial breath sounds were heard over the right supra-mammary and axillary regions. He had hepatosplenomegaly (liver span: 6 cm; spleen: 4 cm). The rest of the systemic examination was normal. Chest radiograph [Figure 1]a revealed right upper and middle zone consolidation with a cavity. His three gastric lavage samples were negative for acid-fast bacilli (AFB). Tuberculin skin sensitivity test (TST, also called Mantoux test) using five tuberculin units was positive (induration of 17 mm) at 48 h. The computed tomography (CT) scan of the thorax [Figure 1]b showed multiple cavities in the right hemithorax. Ultrasonography and CT scans of the abdomen were normal. Mother's chest radiograph [Figure 2] showed multiple cavities bilaterally. Her sputum examination showed AFB on smear. Her ELISA was negative for HIV antibodies. The child was treated with four-drug ATT (Isoniazid 5 mg/kg/d, Rifampicin 10 mg/kg/d, Pyrazinamide 25 mg/kg/d and Ethambutol 25 mg/kg/d) as per Indian Academy of Pediatrics recommendations. He showed clinical response at follow-up one month later, in the form of weight gain of 1 kg with reduction in the consolidation on chest radiograph.{Figure 1}{Figure 2}

This 90-day-old infant represents one of the youngest children with cavitatory tuberculosis reported in the literature. The diagnosis was considered on the basis of cavitatory lesions (demonstrated on chest radiography and tomography) in a child with respiratory symptoms with a positive TST and presence of AFB-positive pulmonary tuberculous infection in the mother (close contact) with child demonstrating clinical response to ATT. [1] Congenital tuberculosis was not considered as the child had no symptoms in the first few days of life (seven days), nor did he have caseating hepatic granuloma on ultrasound/CT scan examination. Although AFB could not be demonstrated in the gastric lavage, the diagnosis of tuberculosis in the infant was supported by the criteria and guidelines developed by Stengen et al., and Nair et al., and Osborne. [2] Cavitatory tuberculosis, usually encountered in adults, has been described in infants, (albeit rarely). Maniar et al., in their series of 75 cases below two years of age with cavitating tuberculosis described five cases aged below three months with the youngest being 45 days old. [3]

Choudhary et al., reported cavitatory pulmonary tuberculosis in a 52-day-old infant. [4] The mechanism for the development of lung cavities in infants could be different from that related to such cavities in adults. It has been divided into two categories: [2] One, poor containment of primary infection with enlargement of the primary (Ghon's) focus with caseous liquefaction, then rupturing into an airway causing endo-bronchial spread of tuberculosis resulting in bronchopneumonic opacification and eventually widespread cystic cavities. [1] Second, lympho-bronchial tuberculosis with distal caseating pneumonia may result in bulging fissures (expansile pneumonia) and thick-walled cavities. [1] It needs to be emphasized that uninformed clinicians may not undertake diagnostic tests for tuberculosis if they are not aware of this unusual form of infantile tuberculosis, thereby delaying institution of effective therapy. There is a danger of the patient being investigated and treated for other infectious causes (such as staphylococci and klebsiella) that present with lung cavities, [5] and for anomalies such as pulmonary sequestration. [6]

This could have disastrous consequences as progressive, uncontained pulmonary tuberculosis in infants may lead to lung destruction and death. Our case report intends to prevent just that.

 Acknowledgments

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