A novel cause of eosinophilic pneumonia: recreational marijuana exposure.

Eosinophilic pneumonia is characterized by pulmonary infiltrates visible on radiography, eosinophilic infiltration into the lung parenchyma, and frequent peripheral eosinophilia. The etiology may be idiopathic or secondary to identifiable causes, including drugs, parasites, toxins, infections, or systemic diseases such as hypereosinophilic syndrome. A 60-year-old man was seen in pulmonary clinic with 4 weeks of cough and wheeze. He was found to have pulmonary infiltrates, a peripheral eosinophilia, and bronchoalveolar lavage demonstrated numerous eosinophils. Careful review of history revealed that the symptoms had started after a recreational exposure to marijuana from a different source than usual. Eosinophilic pneumonia from marijuana has been described once in conjunction with tobacco smoke in the pediatric literature, but to our knowledge this is the first report in the adult literature.