Immunologic evaluation by a pediatric pulmonologist.

Respiratory symptoms are among the most common presentations of inborn errors of immunity (IEI) and acquired immunodeficiencies in children. Pediatric pulmonologists are often the first to evaluate these patients, yet immunologic evaluations remain underutilized due to diagnostic complexity and limited familiarity with immune testing. Not all patients will have access to a timely consultation with an immunologist. This review provides a practical framework to aid pediatric pulmonologists in identifying, evaluating, and managing immune dysfunction in children with respiratory disease. It outlines clinical indicators, such as recurrent infections, bronchiectasis, failure to thrive, and syndromic features, and describes the utility and limitations of key immunologic tests. Stepwise diagnostic strategies are presented, from initial laboratory screening to functional assays and genetic testing. Common IEI with respiratory manifestations, including antibody deficiencies, combined immunodeficiencies, phagocytic disorders, and immune dysregulation syndromes, are reviewed. The article also addresses acquired immunodeficiencies, diagnostic mimics, and principles of pulmonary co-management, including prophylaxis and long-term follow-up. Early recognition and collaborative care can improve outcomes and prevent irreversible pulmonary damage in this vulnerable population.