Changing the Underlying Causes of Recurrent Pneumonia In Children: A Systematic Review

ABSTRACT Background Recurrent pneumonia (RP) is a common diagnosis in children, leading to increased morbidity rates, frequent hospitalizations, and longer treatments. Asthma has traditionally been the most common underlying cause. However, recently, other conditions have emerged. Therefore, our goal was to systematically analyze and compare the changes in the underlying causes of RP. Methods We searched four databases from their inception until November 2024 for studies in children under 18 years with RP, where the underlying causes were described. To compare changes in the prevalence of underlying causes, we divide them into periods I (1999–2013) and II (2014–2024). Results Twenty‐two studies (n = 3440 children with RP) met the final criteria for analysis. In 94% of the patients, an underlying cause was identified. Among the 39 underlying conditions described, the top ten were asthma (15.9%), aspiration (14.1%), congenital heart diseases [CHD] (13.2%), lung/airway congenital malformations (10.7%), immunodeficiency (10.4%), bronchial hyperresponsiveness [BHR] (8.0%), neurological causes (8.02%), atopy (7.3%), gastroesophageal reflux disease [GERD] (4.5%), and recurrent upper respiratory tract infections [URTIs] (3.7%). Notably, compared to Period I, a significant decrease was observed in asthma, aspiration, BHR, chronic rhinosinusitis, recurrent URTIs, middle lobe syndrome, CF, infections, obesity, foreign body aspiration, and pulmonary hemosiderosis/hemorrhage in Period II. In contrast, during Period II, a significant increase in lung/airway congenital malformations, immunodeficiency, CHD, atopy, neurological causes, PCD, bronchopulmonary dysplasia, hematologic diseases, and oromotor incoordination was observed. Conclusions In the last decade, the underlying causes of RP have changed, emphasizing the need for a more comprehensive and tailored diagnostic approach.