Blood eosinophilia is an abnormal laboratory finding defined by the presence of more than 0.5 G/L of eosinophils. The most common causes for it in tropical zones are various forms of helminthic infections. Medication side effects and atopic phenomena are less frequent than in the industrialized countries. It can also result from a systemic condition. Its discovery requires a pragmatic etiological investigation, trial treatments, and follow-up based on screening for chronic blood diseases and for serious visceral injuries linked to chronic tissue eosinophil toxicity.
Keywords: eosinophil; eosinophilia; helminths; traveler.