DDAH2 and eosinophilic granulomatosis with polyangiitis: Middle lobe syndrome (MLS) is defined as recurrent or chronic atelectasis of the right middle lobe of the lung, and it is a potential complication of asthma.<h4>Case presentation</h4>Herein, we describe a case of MLS in a 51-year-old woman, never-smoker, affected by EGPA, presenting exclusively with leukocytosis and elevated concentrations of acute-phase proteins, without any respiratory symptom, cough, or hemoptysis.