The incidence, morbidity and mortality of lung abscesses has fallen due to improved antibiotic therapy and improved early diagnostic capabilities. Overall, lung abscess remains a relatively uncommon disease in the pediatric population. Pathogenesis Risk factors for the development of a lung abscess are aspiration, immunodeficiency and hematogenous spread. In children, a lung abscess may also be a complication of a necrotizing pneumonia. Aspiration occurs in children with neurologic disorders, altered mental status, impaired cough mechanisms, swallowing dysfunction or even foreign body aspiration.
Most lung abscesses related to aspiration are polymicrobial and include anaerobes.
Hematogenous spread occurs with emboli, right sided endocarditis and bacteremia. Immunodeficiency in children occurs secondary to myeloproliferative disorders, chemotherapy, chronic granulomatous disease, hyper IgE syndrome, etc. Additionally, immotile cilia disorders and cystic fibrosis can increase the risk for a lung abscess. A lung abscess can have a well defined fibrotic wall that may converge on adjacent structures causing compression or dissection of the borders. Dissection into a bronchus results in an air fluid level.