Clinical, radiological, and physiological differences between obliterative bronchiolitis and problematic severe asthma in adolescents and young adults: The early origins of the overlap syndrome?

Purpose Few reports have compared chronic obstructive lung diseases (OLDs) starting in childhood. Aims To describe functional, radiological, and biological features of obliterative bronchiolitis (OB) and further discriminate to problematic severe asthma (PSA) or to diagnose a group with overlapping features. Results Patients with OB showed a greater degree of obstructive lung defect and higher hyperinflation (P < 0.001). The most frequent high-resolution computed tomography (HRCT) features (increased lung volume, inspiratory decreased attenuation, mosaic pattern, and expiratory air trapping) showed significantly greater scores in OB patients. Patients with PSA have shown a higher frequency of atopy (P < 0.05). ROC curve analysis demonstrated discriminative power for the LF variables, HRCT findings and for atopy between diagnoses. Further analysis released five final variables more accurate for the identification of a third diagnostic group (FVC%t, post-bronchodilator ΔFEV1 in ml, HRCT mosaic pattern, SPT, and D. pteronyssinus-specific IgE). Conclusions We found that OB and PSA possess identifiable characteristic features but overlapping values may turn them undistinguishable. Pediatr. Pulmonol. 2011; 46:580–580. © 2011 Wiley-Liss, Inc.