Major criteria - all of the following must be present:
(1) The patient is symptomatic (cough, fever and dyspnea). The symptoms may range from mild to severe.
(2) Peripheral infiltrates seen on imaging studies. These may be patchy, nodular, nonsegmental, shifting and/or recurrent)
(3) A biopsy shows an eosinophilic infiltrate of the pulmonary interstitial tissue and alveolar spaces.
(4) Exclusion of organic disorders causing eosinophilia (collagen vascular diseases, parasitic disease, fungal disease, tumors, myeloproliferative disorders, etc)
Minor criteria - not necessary for the diagnosis:
(1) absolute eosinophilia in the peripheral blood
(2) presence of an eosinophilia in a bronchoalveolar lavage.
(3) responsiveness to corticosteroids
