Pulmonary alveolar proteinosis

Abstract

Learning objectives• To recognize the various presentations and appropriate management of pulmonary alveolar proteinosis (PAP). • To understand the various acquired causes of PAP. Pre-test• What is the etiology of PAP?• What are the various differential diagnoses associated with the 'crazy-paving' pattern that need to be considered and ruled out before making a diagnosis of PAP? CASE PRESENTATIONA 32-year-old Caucasian man without a significant medical history presented with a two-month history of progressively worsening dyspnea on exertion. He denied any cough, hemoptysis, chest pain, lower extremity swelling, fevers, chills, night sweats, weight change, new rashes, arthralgias or myalgias. He had no exotic travel or sick contacts. He was a 10 pack-year smoker and occasionally consumed alcohol. He denied any illicit drug use. He worked in construction, and his hobbies included woodworking, in which he was chronically exposed to cement and saw dust. Before his visit to the Mayo Clinic (Minnesota, USA), he was treated by other providers with various courses of antibiotics and prednisone without relief. A review of systems was otherwise unrevealing. On physical examination, the patient's vital signs were as follows: temperature 36.6°C; blood pressure 96/70 mmHg; pulse rate 80 beats/min; respiratory rate 18 breaths/min; and oxygen saturation 88% on room air. Most notably, his lung examination demonstrated scattered inspiratory crackles without any rales, rhonchi or wheezes. The cardiac, vascular, abdominal, lymphatic and integument examinations were all unremarkable.