Eosinophilia Management Guideline

Diagnostic Considerations

For patients with eosinophilia, obtaining a detailed travel history is crucial, as helminth infections are the most common identifiable cause of eosinophilia in returning travelers (diagnosis rates 19-80%) 1
Travelers to areas with endemic helminth infections should be asked about their travel history, and for those traveling to West Africa, specific filarial investigations should be considered 1, 2
A medication review is necessary, as drugs are among the most common non-infectious causes of eosinophilia in countries with low rates of endemic helminth infections, with common culprits including NSAIDs, beta-lactam antibiotics, and nitrofurantoin 1, 3

Stool examination for ova and parasites (three samples on different days) is a first-line test for patients with eosinophilia 4
Serological tests for common helminth infections should be based on travel history 1, 2
If travel history to endemic areas, specific serological tests for schistosomiasis, strongyloidiasis, and filariasis should be considered 1, 2

For mild eosinophilia (500-1500 cells/μL) with travel history to endemic areas and no other obvious cause, empirical treatment with albendazole 400 mg single dose plus ivermectin 200 μg/kg single dose (for patients >24 months of age) may be considered 2
For specific helminth infections identified, targeted therapy (e.g., albendazole 400 mg single dose for hookworm) should be used 4

Even mild persistent eosinophilia can cause end-organ damage if left untreated, according to the Journal of Infection 1
Some helminth infections (e.g., Strongyloides stercoralis) can persist lifelong and later present as hyperinfection syndrome with high mortality in immunocompromised patients, as reported by the Journal of Infection 1
Testing for eosinophilia alone is not an adequate screening strategy for helminth infection, as many people with helminth infections do not have eosinophilia, as stated by the Journal of Infection 1