What are the Causes of Pneumonitis?
- Pneumonia (infection by bacteria, fungi or viruses)
- Inhalation of of stomach contents while vomiting (aspiration pneumonitis)
- Hypersensitivity pneumonitis caused by inhalation of an allergy causing substance - eg, humidifier lung, farmer's lung, bird fancier's lung.
- Autoimmune connective tissue diseases – rheumatoid arthritis, scleroderma, systemic lupus erythematosus (SLE)
- Adverse reaction to drug or toxic chemical eg chlorine, ammonia gas, interferon therapy, amiodarone, nitrofurantoin, aspirin overdose
- Radiation therapy to chest for cancer
- Sepsis caused by overwhelming infection
Risk Factors of Hypersensitivity Pneumonitis
- Bird handlers – Inhalation of bird feathers or bird droppings
- Farmers – Inhalation of droplets of pesticides or airborne particles in moldy hay
- Hot tubs and humidifiers – Inhalations of mold from poorly maintained humidifiers and hot water tubs
