It has long been suggested that infectious agents may trigger sarcoidosis through their infectious or antigenic properties. A patient with airway colonization from P. aeruginosa in the setting of idiopathic bronchiolitis (IB) mimicking diffuse panbronchiolitis (DPB) developed sarcoidosis. Impressive clinical and radiological improvement of both bronchiolitis and sarcoidosis features was achieved with a one-year treatment with low-dose erythromycin, thus suggesting a possible link between the two conditions in this specific case. Pathogenic hypotheses and therapeutic implications are specifically discussed.