What is the appropriate management for a patient with eosinophilia, elevated IgE, dyspnea on exertion, and a history of abdominal pain and hematuria, with normal Computed Tomography (CT) scans and Pulmonary Function Tests (PFTs)?

Management of Eosinophilia with Elevated IgE in a Young Patient

Immediate Priority: Rule Out Helminth Infection

This 16-year-old requires empirical anti-helminthic treatment with albendazole 400 mg plus ivermectin 200 μg/kg as first-line therapy, given the marked eosinophilia (2900 cells/μL), extremely elevated IgE (2500 IU/mL), and history of hematuria suggesting possible parasitic infection. 1, 2

The combination of peripheral eosinophilia, markedly elevated serum IgE, and transient hematuria with abdominal pain strongly suggests helminth infection, even with normal imaging. 3 Helminth infections account for 19-80% of eosinophilia cases and can present with these exact features. 2

Diagnostic Workup Before or Concurrent with Treatment

Essential Investigations

• Obtain three separate concentrated stool specimens for ova and parasites - this is first-line testing for helminth detection, though sensitivity is limited in early infection or with certain parasites. 3, 2

• Serology for Strongyloides stercoralis is critical - this parasite can persist lifelong and cause fatal hyperinfection syndrome if the patient becomes immunocompromised in the future. 3, 2 Strongyloides is particularly important given the hematuria and abdominal pain history. 3

• Serology for Schistosoma species if any freshwater exposure history - the hematuria episode that resolved spontaneously is highly suggestive of Schistosoma haematobium, which causes transient hematuria during egg-laying phases. 3 Schistosomiasis can cause long-term complications including bladder carcinoma and spinal cord involvement. 2

• Toxocara serology (ELISA) - given the elevated IgE and abdominal pain, visceral larva migrans from Toxocara canis should be excluded. 3 This typically presents with marked eosinophilia and elevated IgE in young adults. 4

Additional Testing Based on Travel History

• Detailed travel and exposure history is mandatory - focus on freshwater swimming in Africa/tropical regions, consumption of raw/undercooked meat (especially crab, crayfish, pork), and contact with dogs. 3, 2

• Filaria serology if travel to endemic regions - tropical pulmonary eosinophilia from lymphatic filariasis can present with dyspnea and eosinophilia >3 × 10⁹/L, though typically with more prominent respiratory symptoms. 3, 5

Treatment Algorithm

First-Line Empirical Therapy

Administer albendazole 400 mg as a single dose plus ivermectin 200 μg/kg as a single dose. 1 This combination covers most common helminth infections including:

• Strongyloides stercoralis
• Hookworm
• Ascaris
• Toxocara species 3

Critical Pre-Treatment Screening

Before administering diethylcarbamazine (DEC) for any suspected filarial infection, you must exclude:

• Onchocerciasis co-infection - DEC can cause severe reactions including blindness in co-infected patients. Perform skin snips and slit lamp examination if travel to co-endemic regions. 3

• Loa loa microfilaremia - check blood film for microfilariae. If present, DO NOT use DEC as it may cause fatal encephalopathy. Use corticosteroids with albendazole first to reduce microfilarial load to <1000/ml. 3, 2

Specific Parasite-Directed Therapy

If Schistosomiasis is confirmed or highly suspected:

• Praziquantel 40 mg/kg as a single dose, repeated at 6-8 weeks (eggs and immature schistosomules are relatively resistant to single dosing). 3
• Consider prednisolone 20 mg/day for 5 days if acute Katayama syndrome features present (fever, urticaria, cough). 3

If Tropical Pulmonary Eosinophilia is diagnosed:

• Diethylcarbamazine (DEC) 50 mg day 1, increasing by day 4 to 200 mg three times daily for 3 weeks (after excluding onchocerciasis and Loa loa). 3, 5
• Consider corticosteroids for ongoing alveolitis to prevent pulmonary fibrosis. 5, 6
• Monitor for relapse as 20% require re-treatment. 3, 5

Alternative Diagnoses to Consider

Eosinophilic Granulomatosis with Polyangiitis (EGPA)

While less likely given the age and presentation, EGPA should be considered if:

• Asthma symptoms worsen or develop
• Peripheral neuropathy emerges
• Renal involvement develops 3

Check ANCA (MPO-ANCA and PR3-ANCA) - positive in 30-40% of EGPA cases, with MPO-ANCA being more specific for vasculitis. 3 However, ANCA are usually not present in primary eosinophilic disorders. 3

Eosinophilic Gastroenteritis

The history of lower abdominal pain with eosinophilia and elevated IgE raises the possibility of eosinophilic gastroenteritis. 7, 8

• If abdominal symptoms persist after anti-helminthic treatment, perform upper and lower endoscopy with multiple biopsies - look for ≥50 eosinophils/high power field in the mucosa. 8
• Treatment would be corticosteroids (prednisolone) if confirmed. 8, 6

Other Rare Considerations

• Toxocariasis can cause visceral larva migrans with abdominal pain, eosinophilia, and elevated IgE without prominent respiratory symptoms. 3, 4
• Hypereosinophilic syndrome is unlikely given the normal organ imaging, but requires exclusion if eosinophilia persists >6 months. 2

Follow-Up Strategy

Short-Term (2-4 Weeks Post-Treatment)

• Repeat complete blood count - eosinophil count should decrease significantly if helminth infection was present. 2
• Reassess symptoms - dyspnea and abdominal pain should improve. 3
• Repeat stool studies if initially negative - some parasites have intermittent shedding. 3

Medium-Term (6-8 Weeks)

• Repeat praziquantel if schistosomiasis was treated - immature forms require second dosing. 3
• If eosinophilia persists (≥1.5 × 10⁹/L for >3 months after treating infections), refer to hematology for evaluation of primary eosinophilic disorders. 2

Long-Term Monitoring

• Screen for end-organ damage if eosinophilia persists - cardiac (echocardiogram), pulmonary (PFTs, chest imaging), and neurological assessment. 2
• Strongyloides serology should be repeated at 6-12 months to ensure eradication, as this parasite can persist and cause fatal hyperinfection if immunosuppression occurs later. 3, 2

Critical Pitfalls to Avoid

• Do not assume normal imaging excludes helminth infection - many parasitic infections cause eosinophilia without radiographic abnormalities, especially in early stages. 3

• Do not start corticosteroids before excluding Strongyloides - steroids can precipitate fatal hyperinfection syndrome in undiagnosed strongyloidiasis. 5, 2

• Do not rely solely on single stool sample - sensitivity is poor; three concentrated specimens are required. 3, 2

• Do not use DEC without excluding Loa loa and onchocerciasis - this can cause fatal encephalopathy or blindness. 3, 2

• Do not dismiss the hematuria as insignificant - transient hematuria with eosinophilia is classic for Schistosoma haematobium, which requires specific treatment and has long-term oncogenic risk. 3, 2