Underlying causes of recurrent pneumonia in children

To determine the relative frequency of underlying factors for recurrent pneumonia and the proportion of patients in whom the underlying illness diagnosis was known prior to pneumonia recurrence.

Retrospective medical record review for a 10-year period from January 1987 through December 1997 at The Hospital for Sick Children in Toronto, Ontario, a tertiary care pediatric hospital. Recurrent pneumonia was defined as at least 2 pneumonia episodes in a 1-year period or at least 3 during a lifetime.

Of 2952 children hospitalized with pneumonia, 238 (8%) met criteria for recurrent pneumonia. An underlying illness diagnosis was identified in 220 (92%). Of these, the underlying illness was diagnosed prior to pneumonia in 178 (81%), with the first episode in 25 (11%), and during recurrence in 17 (8%). Underlying illnesses included oropharyngeal incoordination with aspiration syndrome (114 cases [48%]), immune disorder (24 [10%]), congenital cardiac defects (22 [9%]), asthma (19 [8%]), pulmonary anomalies (18 [8%]), gastroesophageal reflux (13[5%]), and sickle cell anemia (10 [4%]). Clinical clues to diagnosis were recurrent infections at other locations and failure to thrive in the cases of an immune disorder, recurrences involving the same location in those with underlying pulmonary pathology, the association of respiratory symptoms with feeding in those with gastroesophageal reflux, or recurrent wheezing in asthmatic children.

Recurrent pneumonia occurs in fewer than one tenth of all children hospitalized with pneumonia. Most of them have a known predisposing factor. The most common cause was oropharyngeal incoordination.