Parasitic Hypereosinophilia in Childhood: a Diagnostic Challenge

Severe hypereosinophilia (HE) in children is rare, and its etiological diagnosis is challenging. We describe a case of a 30-month-old boy, living in a rural area, who was admitted to our Clinic with a 7-day history of fever and severe hypereosinophilia. A comprehensive diagnostic workup could not identify the cause of this condition. On day 6, the rapidly increasing eosinophil count (maximum value of 56,000/mm3), the risk of developing hypereosinophilic syndrome, and the patient's history prompted us to undertake an empiric treatment with albendazole. The eosinophil count progressively decreased following treatment. On day 13, clinical condition and hematological data were satisfactory, therefore the treatment was discontinued, and the patient was discharged. Three months later, anti-nematode IgG antibodies were detected in patient serum, thus establishing the etiological diagnosis. In conclusion, an empiric anthelmintic treatment seems to be justified when parasitic hypereosinophilia is strongly suspected, and other causes have been excluded.