What is the practical management of eosinophilia in children?

Practical Management of Eosinophilia in Children

Begin by determining the absolute eosinophil count (AEC) and immediately assess for life-threatening end-organ damage, particularly cardiac involvement, as this requires urgent intervention regardless of eosinophil level. 1

Immediate Assessment for Critical Complications

• Evaluate for cardiac involvement (Löeffler endocarditis) first, which presents with myocardial fibrosis, systemic thromboembolism, and acute heart failure—the primary cause of mortality in hypereosinophilic syndromes 1
• Eosinophilic myocarditis progresses through necrotic, thrombotic, and fibrotic stages, with particularly high thromboembolism risk during the thrombotic stage 1
• Any patient with evidence of end-organ involvement requires urgent medical assessment regardless of the absolute eosinophil count 1

Classification by Severity

Classify eosinophilia based on AEC:

• Mild: 500-1,500 cells/μL 2, 3
• Moderate: 1,500-5,000 cells/μL 1, 2
• Severe/Hypereosinophilia: ≥5,000 cells/μL 2, 3

Note that hypereosinophilia specifically requires eosinophil count ≥1,500 cells/μL documented on at least two consecutive tests with a minimum 4-week interval 2

Diagnostic Approach by Severity and Clinical Context

For Mild to Moderate Eosinophilia (500-5,000 cells/μL)

Allergic disorders are the most common cause in this range, accounting for approximately 80% of cases 3

• Evaluate for allergic diseases including food allergies, atopic dermatitis, asthma, and allergic rhinitis as the primary differential 3
• Food allergy is an independent risk factor for childhood eosinophilia (OR: 1.866) 3
• In travelers, migrants, or internationally adopted children, parasitic infections (particularly helminths) are the leading cause, with diagnosis rates of 19-80% in these populations 1, 4
• For asymptomatic eosinophilia in children >24 months from endemic areas, empirical treatment with albendazole 400 mg single dose plus ivermectin 200 μg/kg single dose is recommended 1

For Severe Eosinophilia (≥5,000 cells/μL)

Primary immunodeficiencies (PIDs) are the most common etiology in severe cases, particularly in regions with high rates of consanguineous marriages 3

• PIDs are an independent risk factor for childhood eosinophilia (OR: 2.200) and should be investigated when allergic or infectious causes are excluded 3
• Values >20,000 cells/μL are highly suggestive of myeloproliferative disorders 2
• Malignancies account for approximately 0.8% of cases but can present at any severity level 3

Specific Parasitic Considerations

Helminths are the most common identifiable cause in returning travelers or migrants 1

Critical parasites requiring specific attention:

• Strongyloides stercoralis: Can persist lifelong and present as hyperinfection syndrome with high mortality in immunocompromised patients 1
• Schistosoma haematobium: Associated with squamous cell bladder carcinoma 1
• Helminths are particularly likely in older children with eosinophil counts >1,000 cells/μL 4

When to Refer to Hematology

Refer immediately if:

• Eosinophilia ≥1,500 cells/μL persists for >3 months after infectious causes are excluded or treated 1
• Evidence of end-organ damage at any eosinophil level 1
• Suspicion for myeloproliferative disorders or malignancy 2, 3

Management of Eosinophilic Gastrointestinal Disease

If eosinophilic esophagitis or gastrointestinal involvement is identified:

Start with single modality therapy—for most patients, pharmacotherapy is preferred over dietary restriction 5

Pharmacological Options:

• Proton pump inhibitors (PPIs): Omeprazole 20 mg twice daily for 8-12 weeks 6
• Topical corticosteroids are highly effective for eosinophilic inflammation in the gastrointestinal tract 6
• If PPI therapy causes unwanted side effects (diarrhea, gastrointestinal infections, or magnesium deficiency), switch to alternative treatments such as diet or topical steroids 5

Dietary Management:

• All pediatric patients embarking on dietary management should be managed by a multiprofessional team including an experienced clinician, specialist dietitian, and for selected patients, an allergist 5
• Allergy testing (skin prick, specific IgE, patch testing) is NOT recommended for choosing dietary restriction therapy 5
• Combination therapy of drugs and diet should be reserved for patients who fail monotherapy 5

Important Monitoring in Children:

• Monitor bone mineral density and adrenal suppression in children and adolescents on topical corticosteroids, though systemic side effects have not been documented during long-term treatment 5
• Candida infection may occur in a small proportion treated with topical corticosteroids and should be managed with topical antifungals while continuing topical steroids 5
• Appreciate and discuss the psychological impact of dietary therapy with patients and carers, as anxiety and depression affect patients due to persistent symptoms and social restrictions 5

Ongoing Monitoring

For persistent hypereosinophilia (≥1,500 cells/μL):

• Regular clinic visits to assess symptoms, compliance, and adverse effects 1, 6
• Serial cardiac imaging if cardiac involvement was present 1
• Endoscopy with biopsy to evaluate histological response in gastrointestinal disease, as symptoms do not always correlate with histological activity 6

Key Clinical Pearls

• In children with unexplained eosinophilia, independent risk factors for no identifiable cause include: younger age (≤2 years), absence of symptoms, and mild eosinophilia (<1,000/μL) 4
• The median duration of eosinophilia is approximately 7 months, shortest in severe cases (2 months) 3
• When an etiology is identified and treated, eosinophilia resolves in approximately 52% of cases within a median of 7 months 4
• Eosinophilic disorders are the most common cause of spontaneous esophageal perforation, which can occur at any age 5, 6