CASE PRESENTATION: A 62 year old male with 25 year history of working in a cardboard factory presented with complaints of dyspnea, cough, malaise. He has been symptomatic for 20 years but was diagnosed with asthma and treated with albuterol with poor control and frequent recurrence. Exam revealed bilateral rales. Computer tomography (CT) of the chest showed extensive upper lobe pulmonary interstitial and alveolar lung disease. Bronchoalveolar lavage (BAL) showed intense eosinophilia (99%) and pathology exam of wedge resection of right middle lobe was consistent with CEP with features of organizing pneumonia. Prednisone 40mg daily was started but tapered to 20 mg over 6 months with continued employment. He began requiring oxygen at 3 L/min, received short term disability, and stopped working. 4 months later, a repeat CT showed stable ground glass opacities and increased interstitial markings. Spirometry revealed FEV1 49%, FVC 45%, and DLCO was 29% predicted. BAL demonstrated persistent yet improved eosinophilia (30%).