A case of refractory chronic respiratory tract infection due to Pseudomonas aeruginosa successfully controlled by combination of clarithromycin and azithromycin.

The prognosis of patients with chronic respiratory tract infections, especially diffuse panbronchiolitis, is remarkably improved by long-term administration of low-dose macrolides. However, in some cases, patients are refractory to macrolide treatment and show a low or no response; therefore, new treatment strategies are required. Here we present a patient refractory to either single low-dose clarithromycin or azithromycin but responded remarkably to the combination usage of both macrolides.