Transitory Pulmonary Infiltration

(Loeffler's Syndrome)

¹ The Department of Medicine, Marquette University School of Medicine, Milwaukee, Wisconsin.

1. Three cases of Loeffler's syndrome are discussed. In each instance, atopic rhinitis and asthma were present and sensitivities to multiple inhalant allergens were demonstrated.

2. Presumably, polyvalent bacterial or intrinsic sensitivities were present in all three patients in addition to recognized extrinsic sensitivities. It is difficult and often impossible in the presence of multiple sensitivities to incriminate any single antigen as the cause of an episode of allergic pulmonary infiltration.

3. In two of the patients described, pulmonary infiltrations were characteristically transitory. In the third patient, although early infiltrations were of fleeting character, repeated attacks have left increasing residual fibrosis and evidence of irreversible damage. It is believed that irreversible changes after allergic pulmonary infiltrations are especially apt to occur when so-called intrinsic or bacterial sensitivities are present.