Exogenous lipoid pneumonia associated with nasal decongestants use: A narrative review of an under recognized clinical entity

Table 1 Comparison of exogenous vs endogenous lipoid pneumonia

Feature	Exogenous Lipoid Pneumonia	Endogenous Lipoid Pneumonia
Etiology	Inhalation or aspiration of exogenous lipid substances (e.g., nasal oils, mineral oil)	Lipid accumulation from cell breakdown due to bronchial obstruction (e.g., tumors, infections)
Common risk groups	Elderly, children, chronic users of oil-based nasal sprays	Patients with obstructive pulmonary diseases or malignancies
Onset	Often insidious, related to exposure history	Secondary to underlying lung pathology
Radiological findings	Ground-glass opacities, consolidations, low-attenuation areas	Cholesterol clefts, mass-like lesions, variable opacities
Histological features	Lipid-laden macrophages, lipid vacuoles, granulomas	Cholesterol crystals, foamy macrophages, associated necrosis
BAL findings	Numerous lipid-laden macrophages (positive on Oil Red O stain)	Foamy macrophages may be present, but lipid content endogenous
Management	Discontinue exposure; corticosteroids in severe cases	Treat underlying cause (e.g., tumor, obstruction); supportive care
Prognosis	Generally favorable if caught early	Depends on resolution of underlying pathology

BAL: Bronchoalveolar lavage.