HYPEREOSINOPHILIA

Key words: Hypereosinophilia, Infection, Immunodeficiency, Lymphoproliferative disorders, Diagnosis

Blood eosinophilia, especially if found fortuitously, often remains poorly understood. This article provides a diagnostic approach to hypereosinophilia, focusing on the context in which these data are found. The diagnostic evaluation of hypereosinophilia with no other symptoms should consider the level of eosinophils and the duration and trend of hypereosinophilia. A count greater than 1,500/μl is the proposed cut-off because it is potentially associated with organ damage. Common infections account for most hypereosinophilias and are often transient and difficult to define. Other common causes include parasite infections while lymphoproliferative disorders and hypereosinophilic syndrome genetically determined are rarer. On the other hand, eosinophilia might also be associated with other specific conditions such as immunodeficiency disorders or specific eosinophilic disorders. However, in the latter cases, other specific signs and symptoms, rather than hypereosinophilia alone command diagnostic iter.