Disease Information for Loeffler's Eosinophilic Pneumonitis, acute/PIE

Eosinophilia and pulmonary infiltrate (PIE) is Loeffler"s syndrome with many causes; allergic pneumonitis usually from extrinsic allergens; for long diagnostic cause list see attribute Loeffler"s syndrome (PIE); usually treatment includes steroids; can be severe with fibrosis if antigen exposure is recurrent; hypersensitivity pneumonitis is a more acute variation;------------------------------ diseases of known or unknown etiology characterized by eosinophilic pulmonary infiltrates and, commonly, peripheral blood eosinophilia; Eosinophilic pneumonia is sometimes called the pulmonary infiltrates with eosinophilia (PIE) syndrome; Causes include parasites (eg, roundworms, Toxocara larvae, filariae), drugs (eg, penicillin, aminosalicylic acid, hydralazine, nitrofurantoin, chlorpropamide, sulfonamides), chemical sensitizers (eg, nickel carbonyl inhaled as a vapor), and fungi (eg, Aspergillus fumigatus, which causes allergic bronchopulmonary aspergillosis; Most eosinophilic pneumonias, however, are of unknown etiology, although a hypersensitivity mechanism is suspected; Eosinophilia suggests a type I hypersensitivity reaction; other features of the syndrome (vasculitis, round cell infiltrates) suggest type III and possibly type IV reactions;

Eosinophilic pneumonias are often associated with bronchial asthma; Those associated with asthma and those of unknown etiology can be classified into three general groups: extrinsic bronchial asthma with the PIE syndrome, which often is allergic bronchopulmonary aspergillosis; intrinsic bronchial asthma with the PIE syndrome (chronic eosinophilic pneumonia), commonly with characteristic peripheral infiltrates on chest x-ray; and allergic granulomatosis (Churg-Strauss syndrome), a variant of polyarteritis nodosa with a predilection for the lungs; [Acute]Simple eosinophilic pneumonia (Löffler"s syndrome) may occasionally be associated with mild asthma; Eosinophilic pneumonias not associated with asthma include acute eosinophilic pneumonia, the eosinophilia-myalgia syndrome, and the hypereosinophilic syndrome; Acute eosinophilic pneumonia, a distinct entity of unknown cause, results in acute fever, severe hypoxemia, diffuse pulmonary infiltrates, and > 25% eosinophils in bronchoalveolar lavage fluid; it resolves promptly and completely with corticosteroid therapy; [Merck Manual 17th]

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