Does a parent-reported history of pneumonia increase the likelihood of respiratory symptoms needing therapy in asthmatic children and adolescents?

Background. Asthmatic children and adolescents attending outpatient clinics often have a history of pneumonia. Whether respiratory symptoms, lung function, and airway inflammation differ in asthmatic patients with and without a history of pneumonia remains controversial. Aims. To compare clinical, lung functional, and inflammatory variables in asthmatic outpatients with and without a history of pneumonia. Methods. In 190 asthmatic outpatients, aged 6-18 years, we assessed respiratory symptoms, lung function (flows, volumes, and pulmonary diffusion capacity, DLCO/VA), and atopic-airway inflammation as measured by the fractional concentration of exhaled nitric oxide (FENO). A previous medical and radiological diagnosis of pneumonia was defined as "recurrent pneumonia" if subjects had at least three pneumonia episodes or two episodes within a year. Results. Of the 190 outpatients studied, 38 (20%) had a history of pneumonia. These patients had more frequent upper-respiratory symptoms, nighttime awakenings in the past 4 weeks, daily use of inhaled corticosteroids, and lower FENO than the 152 asthmatic children without previous pneumonia (FENO: 20.6 ppb, 95% CI: 15.2-28.0 vs. 31.1 ppb, 95% CI: 27.0-35.8; p < .05). Of the 38 patients with previous pneumonia, 14 had recurrent pneumonia. Despite comparable lung volumes and flows, they also had lower DLCO/VA than asthmatic children with no recurrent pneumonia and asthmatic children without previous pneumonia (DLCO/VA%: 91.2 +/- 11.3 vs. 108.5 +/- 14.7 vs. 97.9 +/- 18.6, p < .05). Conclusion. Respiratory assessment in asthmatic children and adolescents with a history of pneumonia, especially recurrent pneumonia, often discloses symptoms needing corticosteroid therapy, and despite normal lung volumes and flows, mild reductions in the variables reflecting gas diffusion and atopic-airway inflammation (DLCO/VA and FENO). Whether these respiratory abnormalities persist in adulthood remains an open question.