Lipoid Pneumonia From Bug Spray: A Case Report.

Exogenous lipoid pneumonia is an uncommon inflammatory lung disease caused by the aspiration or inhalation of lipid-containing substances. Clinical presentation is highly variable, ranging from asymptomatic disease to progressive respiratory failure, and the condition is often underrecognized in clinical practice. Diagnosis can be challenging because of nonspecific symptoms and imaging findings. We report a case of a 38-year-old woman with suspected exogenous lipoid pneumonia associated with exposure to a commercially available bug spray containing plant-based oils. Bronchoscopy with bronchoalveolar lavage revealed eosinophilia and a markedly elevated lipid-laden macrophage index, supporting the diagnosis of lipoid pneumonia. The patient was treated with systemic corticosteroids and advised to avoid further exposure, resulting in clinical improvement and near-complete radiographic resolution on follow-up imaging. This case highlights the importance of obtaining a detailed exposure history in patients with persistent respiratory symptoms, as recognition of lipid exposure can facilitate timely diagnosis and targeted management.