The best prevention is to avoid exposure to the antigen, but this may be impractical if a person can't change jobs. Eliminating or reducing dust or wearing protective masks may help prevent a recurrence. Chemically treating hay or sugarcane waste and using good ventilation systems help prevent workers from being exposed and becoming sensitized to these materials. People who have an acute episode of hypersensitivity pneumonitis usually recover if further contact with the substance is avoided. If the episode is severe, corticosteroids, such as prednisone, reduce symptoms and may help reduce severe inflammation.
Eosinophils participate in the immune defense of the lung.
The number of eosinophils increases during many inflammatory and allergic reactions, including asthma, which frequently accompanies certain types of eosinophilic pneumonia. Blood vessel walls may also be invaded by eosinophils, and the narrowed airways may become plugged with mucus if asthma develops. The exact reason that eosinophils build up in the lungs isn't well understood, and often it isn't possible to identify the substance that's causing the allergic reaction. But some known causes of eosinophilic pneumonia include certain drugs, chemical fumes, and fungal and parasitic infections and infestations. Symptoms and Diagnosis Symptoms may be mild or life threatening.