Humidifier-Related Lung Injury Leading to Hypersensitivity Pneumonitis: A Case Report

Humidifier lung is a subtype of hypersensitivity pneumonitis (HP) triggered by repeated exposure to an antigen. The mainstay of therapy is antigen avoidance. A Caucasian male in his 30s presented with a six-month history of progressively worsening dyspnea and cough. On presentation, he was hypoxic on room air. Laboratory work was significant for a leukocytosis and a CT angiogram of the chest demonstrated diffuse ill-defined ground-glass opacities in both lungs. The patient was admitted for community-acquired pneumonia, but his symptoms worsened, so additional infectious and rheumatological work-up was obtained. History revealed the patient used a home humidifier daily for the past year. Cultures obtained from the humidifier grew