What is simple pulmonary eosinophilia?

Loeffler's pneumonia, occasional malaise, fever, cough, migratory infiltrates and peripheral eosinophilia (minimal or abscent) Resolves without Rx within 4 weeks with excellent prognosis Imaging: migratory peripheral densities. Etiologies: parasite, drug rxn, idiopathic (1/3 of cases)