ABSTRACT
Pulmonarydisease affecting themajor airways and/or parenchymaassociated
with either blood and/or tissue eosinophilia is termed as eosinophilic lung disease. The first four cases with minimal respiratory symptoms, fleeting
pulmonary infiltrates in chest X rays and peripheral blood eosinophilia were
described by Loffler (1) in 1932 and he thought that it was caused by a variety
of antigens. Zumla and James (2) stated that it wasMuller who, after ingesting
Ascaris ova and producing respiratory disease similar to that described by Loffler, attributed the syndrome to the pulmonary phase of ascariasis. Reeder
and Goodrich (3) termed this condition as pulmonary infiltrate with eosino-
philia (PIE) syndrome. Crofton et al. (4) classified PIE syndrome into five groups based on clinical manifestations: simple pulmonary eosinophilia
(Loffler’s syndrome), prolonged pulmonary eosinophilia, pulmonary eosino-
philia with asthma, tropical eosinophilia, and polyarteritis nodosa. Leibow
and Carrington (5) subsequently added chronic eosinophilic pneumonia to the
classification.Basedon theobservation that eosinophils are an integral andcon-
sistent part of the lung inflammation, Allen andDavis (6) classified eosinophilic
lung disease into 10 entities: simple pulmonary eosinophilia, chronic eosinophilic pneumonia, acute eosinophilic pneumonia, Churg-Strauss
syndrome, idiopathic hypereosinophilic syndrome, asthma, allergic
bronchopulmonary aspergillosis, bronchocentric granulomatosis, certain
parasitic infections and certain drug reactions. Savani and Sharma (7)
classified eosinophilic lung diseases into two subgroups: (i) intrinsic (pri-
mary, cryptogenic) in which the cause is not known and (ii) extrinsic (sec-
ondary) in which the cause is known. Although all types of eosinophilic
lung diseases are encountered in the tropics as in other parts of the world, the diseases that are particularly prevalent in the tropics are due to parasitic
infestations and certain infections. The important diseases that can cause
eosinophilic lung diseases in the tropics are listed in Table 1.
