Treatment for Elevated Eosinophils
Diagnostic Approach Before Treatment
- A systematic evaluation for underlying causes is essential before initiating treatment, with referral to appropriate specialists based on clinical presentation and severity of eosinophilia 1
- Assess for common causes including parasitic infections, especially in those with travel history 1, 2
- Assess for common causes including allergic conditions, such as rhinitis, asthma, and atopic dermatitis 1
- Assess for common causes including gastrointestinal disorders, particularly eosinophilic esophagitis 1, 3
- Diagnostic workup should include stool microscopy and serology for parasitic infections 1, 2
- Diagnostic workup should include endoscopy with multiple biopsies if gastrointestinal symptoms are present 1, 3
- Referral to hematology for persistent eosinophilia ≥1.5 × 10⁹/L for more than 3 months 2
Treatment Algorithm
For Parasitic Infections
- Albendazole 400 mg as a single dose for most helminth infections 1, 2
- For strongyloidiasis, ivermectin 200 μg/kg daily for 1-2 days 1, 2
- For schistosomiasis, praziquantel 40 mg/kg in two divided doses for 1 day 2
- For returning travelers with asymptomatic eosinophilia, empiric treatment with albendazole 400 mg single dose plus ivermectin 200 μg/kg single dose 1, 2
For Eosinophilic Esophagitis
- Proton pump inhibitor therapy twice daily for 8-12 weeks 2
- Topical steroids for histological and clinical remission 2, 3
- Two-food elimination diet (milk +/- wheat or egg) for 8-12 weeks with dietitian support 2
For Hypereosinophilic Syndrome and Idiopathic Eosinophilia
- Corticosteroids are first-line therapy for hypereosinophilic syndrome 4
Monitoring Response
- Follow-up eosinophil counts should be obtained after treatment to assess response 1, 2
- For eosinophilic esophagitis, histological remission is defined as <15 eosinophils per 0.3 mm² in tissue biopsies 1
- For persistent eosinophilia despite treatment, consider referral to a hematologist for further investigation 2
Important Considerations
- Persistent eosinophilia of any degree can cause significant end-organ damage, particularly affecting the heart, lungs, and central nervous system 2
Pitfalls and Caveats
- Many people with helminth infection do not have eosinophilia, so testing for eosinophilia alone is not an adequate screening strategy 2
- Peripheral blood eosinophil counts may not always correlate with tissue eosinophilia in conditions like eosinophilic esophagitis 1, 5
- Allergy testing to foods is not recommended for choosing dietary restriction therapy for eosinophilic esophagitis 1