Not Just a Pneumonia…

Introduction: A lung abscess is an uncommon pediatric problem, characterized by a thick-walled cavity (larger than 2 centimeters) in the pulmonary parenchyma that contains purulent material resulting from a pulmonary infection.

The pathogenesis of lung abscess involves an area of initial pneumonitis that leads to necrosis, cavitation and abscess formation. It is classified as primary, or secondary, based upon the existence of pre-existing conditions.

The diagnosis is usually made on chest radiography, however, the use of computed tomography scan may facilitate the distinction between a lung abscess and other conditions such as necrotizing pneumonia.

Clinical Case: A 2-year-old boy, previously healthy, was admitted to the pediatric department following 10 days of fever and cough despite 7 days of treatment with oral amoxicillin/clavulanic acid.

Examination revealed tympanic temperature 37,4 ºC, oxygen saturation 96% in ambient air, auscultation with soft crackles over the right chest. Examination of other systems was normal.

The peripheral blood count showed a hemoglobin of 10,1g/dL, leukocytosis of 16,000/uL with a differential neutrophil count of 73,8% and a C-reactive protein of 247mg/L. Blood cultures were negative.

The chest radiograph revealed a rounded cavity involving the left hemithorax and the possibility of lung abscess was considered.

The computed tomography scan described a parenchymal consolidation of the left lower lobe with necrosis and parenchyma cavity with hydro aerial level.

The clinical signs resolved within 24 hours of initiation of therapy with intravenous ampicillin 400 mg/kg/day and clindamycin 30 mg/kg/day.

After 2 weeks of treatment, the chest radiograph showed a marked reduction of the

abscess.

This treatment was continued for 3 weeks, when it was changed to oral clindamycin for an additional week.

Conclusion: In conclusion, lung abscess is infrequent in infants and children.

The initial choice of treatment is conservative management and the prognosis is usually very good.