Coexistence of diffuse panbronchiolitis and asthma: reciprocity of neutrophilic and eosinophilic inflammation

Diffuse panbronchiolitis (DPB) and asthma are obstructive airway diseases, the former being characterized by Th1‐type and the latter by Th2‐type airway inflammation. Differential diagnosis is often a problem, but coexistence has rarely been reported. A 76‐year‐old man with asthma was admitted to our hospital because of one‐month history of dyspnoea on exertion with bilateral diffuse granular shadows. He also had a history of chronic sinusitis. Auscultation of the lungs showed coarse crackles and wheezes. Laboratory data revealed an elevated total serum immunoglobulin E and a high titre of cold agglutinin. Bronchoscopic evaluations of the shadows revealed compatible pathological findings in both DPB and asthma. Low‐dose macrolide caused a prompt reduction of symptoms, along with improvements in radiographic findings and pulmonary functions, whereas the eosinophilic airway inflammation transiently worsened. When DPB and asthma coexist, the balance of Th1/Th2 immune response may be reciprocally altered by therapeutic intervention.