What is the treatment approach for hypereosinophilia?

Treatment Approach for Hypereosinophilia

The first-line treatment for hypereosinophilic syndrome (HES) is prednisolone 30-60 mg/day to reduce eosinophil counts and mitigate organ damage. 1

Diagnostic Criteria and Evaluation

Before initiating treatment, proper diagnosis is essential:

• HES requires:

  • Persistent eosinophilia >1.5 x 10^9/L
  • Evidence of eosinophil-mediated organ damage
  • Exclusion of secondary causes 1

• Comprehensive evaluation should include:

  • Complete blood count with differential
  • Peripheral blood smear
  • Comprehensive metabolic panel with liver function tests
  • Urinalysis with protein-to-creatinine ratio
  • C-reactive protein
  • Serum tryptase
  • Vitamin B12 levels 1

Treatment Algorithm

1. Treat Secondary Causes First

• Parasitic infections:

  • Strongyloidiasis: ivermectin 200 μg/kg/day for 1-2 days
  • Toxocariasis: albendazole 400mg twice daily for 5 days
  • Schistosomiasis: praziquantel 40 mg/kg twice daily for 5 days
  • Filariasis: diethylcarbamazine (specialist consultation)
  • Hookworm: albendazole 400 mg daily for 3 days 1

• Allergic disorders:

  • For eosinophilic esophagitis: topical steroids (fluticasone 440-880 mg twice daily for adults) 1

2. Treatment for Idiopathic Hypereosinophilic Syndrome

• First-line therapy:

  • Prednisolone 30-60 mg/day 1

• For steroid-refractory cases:

  • Biologic agents: anti-IL-5 therapies (mepolizumab) or anti-IL-5 receptor antibodies (benralizumab) 1
  • Consider IVIG in selected cases with type 1 autosomal dominant HIES 2
  • IFN-γ may be considered in selected cases, though evidence is limited 2

• For specific genetic variants:

  • DOCK8 deficiency with poor antibody production: IgG replacement therapy 2

• For severe cases:

  • Hematopoietic stem cell transplantation (HSCT) should be considered for both forms of HIES 2

Monitoring and Follow-up

• Regular monitoring of eosinophil counts
• Assessment for resolution of symptoms
• Vigilance for end-organ damage, particularly cardiac complications 1
• For patients with HIES:
  • Aggressive therapeutic and prophylactic antibiotic therapy
  • Consider antifungal prophylaxis
  • Monitor for scoliosis in children
  • Extract retained primary teeth 2

Special Considerations

• The main cause of mortality in patients with type 1 HIES is severe infections 2
• Patients with type 1 HIES can have progressive decrease of lung function due to frequent pneumonias 2
• In type 2 HIES, lymphoma and vasculopathy are the most prominent life-threatening complications 2

Common Pitfalls

1. Failure to identify and treat underlying causes before initiating symptomatic treatment
2. Inadequate monitoring for organ damage in patients with persistent eosinophilia
3. Delayed consideration of HSCT in appropriate candidates
4. Overlooking antibiotic prophylaxis in patients with HIES who are prone to recurrent infections
5. Insufficient dose or duration of corticosteroid therapy in idiopathic HES

Remember that the goal of treatment is not just to normalize eosinophil counts but to prevent or mitigate organ damage caused by eosinophil-mediated inflammation.