Pulmonary alveolar proteinosis in association with household exposure to fibrous insulation material

We report the case of a 35-year-old. woman who developed pulmonary alveolar proteinosis requiring multiple lavage treatments, in association with hous ehold exposure to ventilation system dust comprised at least partially by a cellulose fire-resistant fibrous insulation material. Scanning electron mi croscopy with energy-dispersive x-ray analysis documented the presence of s pectral peaks consistent with the insulation material in transbronchial bio psy tissue. The patient showed symptomatic improvement once exposure to the insulation material had ceased. We believe that this case demonstrates an unusual association with pulmonary alveolar proteinosis. This case emphasiz es the broad differential diagnosis for this histologic injury pattern and the need to thoroughly investigate environmental exposures in patients with unexplained pulmonary disease.