What is the appropriate management for a patient with elevated eosinophils (eos), considering their past medical history of allergies, asthma, or eczema?

Management of Elevated Eosinophils in Patients with Allergies, Asthma, or Eczema

In patients with elevated eosinophils and a history of allergies, asthma, or eczema, immediately assess for symptoms of esophageal dysfunction (dysphagia, food impaction) and refer for allergy/immunology evaluation, as 50-80% of patients with eosinophilic esophagitis have concurrent atopic disease, and peripheral eosinophilia alone is neither sensitive nor specific for tissue eosinophilia. 1

Initial Clinical Assessment

Determine the Degree of Eosinophilia

• Mild eosinophilia (0.5-1.5 × 10⁹/L) is most commonly caused by allergic disorders or medications in non-endemic areas, but helminth infections remain the leading cause in travelers or migrants (19-80% of cases). 2

• Moderate to severe eosinophilia (≥1.5 × 10⁹/L) requires hematology referral if persisting >3 months after infectious causes are excluded or treated. 2

• Peripheral eosinophilia occurs in only 10-50% of adults and 20-100% of children with eosinophilic esophagitis, making tissue diagnosis essential rather than relying on blood counts alone. 1

Screen for Red Flag Symptoms Requiring Urgent Evaluation

• Dysphagia or food impaction warrants upper endoscopy with multiple biopsies (minimum 6 biopsies: 2-3 from proximal and 2-3 from distal esophagus) to evaluate for eosinophilic esophagitis. 2

• Cardiac symptoms (chest pain, dyspnea, heart failure symptoms, arrhythmias) require immediate ECG, cardiac troponin, NT-proBNP, and echocardiography, as eosinophil-mediated cardiac damage can be irreversible. 2

• Pulmonary symptoms (persistent cough, wheezing, infiltrates on imaging) necessitate chest X-ray and pulmonary function tests. 2

• Neurological symptoms (altered mental status, focal deficits, peripheral neuropathy) demand prompt assessment with EMG and potential nerve biopsy. 2

Mandatory Allergy/Immunology Referral

A thorough evaluation by an allergist or immunologist is recommended because 40-75% of patients with eosinophilic esophagitis have allergic rhinitis, 14-70% have asthma, and 4-60% have eczema. 1

Specific Testing to Perform

• Aeroallergen sensitization testing (skin prick tests or serum-specific IgE) is warranted, as 71-93% of patients with eosinophilic esophagitis have positive tests to outdoor aeroallergens (grass, weeds, trees, molds) and 16-69% to indoor allergens (dog, cat, cockroach, dust mites). 1

• Seasonal variation assessment is important, as tree and grass pollen levels directly correlate with eosinophilic esophagitis diagnoses, with decreased diagnoses in winter and increased diagnoses in spring, summer, and fall. 1

• Food allergy evaluation should assess for IgE-mediated immediate hypersensitivity (15-43% of patients with eosinophilic esophagitis) and potential anaphylaxis risk, as patients may require epinephrine prescription. 1

Critical Caveat About Allergy Testing

Allergy testing (skin prick, specific IgE, patch testing) is NOT recommended for choosing dietary restriction therapy for eosinophilic esophagitis, as targeted dietary elimination based on IgE testing is no more effective than empirical dietary elimination. 1

Exclude Parasitic Infections Before Attributing Eosinophilia to Atopy

Travel History is Essential

• Obtain detailed travel history focusing on fresh water exposure in Africa/tropical regions, raw/undercooked meat consumption, and timing of travel relative to eosinophilia onset. 2

• Helminth infections account for 19-80% of eosinophilia cases in returning travelers or migrants, even in patients with known atopic disease. 2

Parasitic Workup for Any Eosinophilia >0.5 × 10⁹/L with Travel History

• Stool microscopy for ova and parasites (3 separate concentrated specimens) is first-line testing. 2

• Strongyloides serology and culture must be sent immediately, as Strongyloides can persist lifelong and cause fatal hyperinfection syndrome in immunocompromised patients. 2

• Schistosomiasis serology if fresh water exposure in endemic areas occurred. 2

Important Limitation

• Many helminth-infected patients do not have eosinophilia, so normal eosinophil counts do not exclude parasitic infection—only tissue-invasive helminths cause eosinophilia. 2

Management of Eosinophilic Esophagitis When Diagnosed

Diagnostic Criteria

• Eosinophilic esophagitis is diagnosed when >15 eosinophils per high-power field are present on esophageal biopsy after excluding GERD. 2

• Histological remission is defined as <15 eosinophils per 0.3 mm², and deep remission as <5 eosinophils per 0.3 mm². 2

First-Line Treatment Options

Topical swallowed corticosteroids (fluticasone or budesonide) are recommended over no treatment, with strong evidence showing they fail to induce histologic remission in only one-third of treated patients compared to >85% of placebo patients. 1

• Proton pump inhibitors may be used as initial therapy, with an overall histologic response rate of 42%, though they fail to induce remission in approximately two-thirds of treated patients. 1

• Topical corticosteroids decrease blood eosinophil counts in 88% of patients following treatment. 1

Dietary Therapy Considerations

• Dietary elimination should be reserved for patients who fail pharmacotherapy or strongly prefer dietary management, as it requires motivation, multiple endoscopies, and specialist dietitian support. 1

• Exclusive elemental diets have high efficacy but low concordance rates and should be reserved for patients refractory to other treatments. 1

• Combination therapy of drugs and diet should only be used for selected patients who fail monotherapy and have access to a multiprofessional team. 1

Maintenance and Monitoring

• Maintenance therapy is mandatory after achieving remission, as clinical relapse rates are high after topical steroid withdrawal. 2

• Repeat endoscopy with biopsies if symptoms recur during treatment to assess histological response. 2

• For patients with persistent dysphagia despite histological remission, consider high-resolution manometry to evaluate for motility disorders. 2

• Endoscopic dilation is safe and effective for fibrostenotic disease but must be combined with anti-inflammatory therapy for optimal outcomes. 2

Monitoring for Concurrent Atopic Disease Control

• Additional testing for asthma and allergies is recommended to improve diagnosis and control of concurrent atopic diseases, as the complex interplay among multiple allergic diatheses affects overall management. 1

• Appropriate aeroallergen avoidance measures should be recommended, as aeroallergens might have a complementary role in eosinophilic esophagitis pathogenesis. 1

Common Pitfalls to Avoid

• Do not assume peripheral eosinophilia alone is adequate for screening tissue eosinophilia, as tissue biopsy is the gold standard for eosinophilic esophagitis diagnosis. 2

• Do not rely solely on peripheral eosinophil counts to assess disease activity, as correlation with tissue eosinophilia and disease activity is unknown. 1

• Do not wait for symptoms to develop before investigating persistent moderate-to-severe eosinophilia, as end-organ damage can be subclinical initially. 2

• Do not attribute severe leukocytosis to allergic disease, as allergic disorders cause only mild elevations—severe elevations warrant hematology evaluation for myeloproliferative disorders. 3