Loffler's endocarditis presenting in 2 children as fever with eosinophilia.

Hypereosinophilic syndromes are defined by the presence of peripheral and bone marrow eosinophilia and by the infiltration of multiple organs by mature eosinophilic cells. Loffler's endocarditis is a condition in which mature eosinophils infiltrate and damage the endocardium and myocardium. Male adults who live in the tropics are the population predominantly affected by this condition. Typical clinical features include weight loss, fever, cough, rash, and congestive heart failure. In this article, we report the typical presentation of an unusual illness that occurred in 2 pediatric patients in different geographic locations. In addition, we believe that these are the youngest patients with Loffler's endocarditis reported.