What is the role of allergy testing in the management of Eosinophilic Esophagitis (EOE)?

Role of Allergy Testing in the Management of Eosinophilic Esophagitis (EOE)

Allergy testing has limited clinical utility in identifying food triggers for EOE and should not be used as the primary method to guide dietary elimination therapy. 1

Relationship Between EOE and Allergies

EOE is strongly associated with allergic conditions, with 50-60% of patients having a history of atopy 2. The allergic profile of EOE patients includes:

• 40-75% have allergic rhinitis
• 14-70% have asthma
• 4-60% have eczema
• 15-43% have IgE-mediated food hypersensitivity 2

Despite these associations, the relationship between EOE and food allergies is complex and not primarily IgE-mediated.

Types of Allergy Testing and Their Limitations

Food Allergen Testing

• Skin Prick Tests (SPT) and Serum-specific IgE Tests:

  • Poor predictive value for identifying EOE food triggers 1, 3
  • 49.2% of patients on allergy testing-based elimination diets fail to achieve histologic remission 2
  • Positive predictive value is generally low to moderate 4

• Atopy Patch Tests (APT):

  • Limited success in identifying food triggers 5
  • May have better results when combined with other tests 4

Aeroallergen Testing

• May be warranted due to:
  • High rates of aeroallergen sensitization (24-78% in adults, 42-93% in children) 2
  • Seasonal variability in EOE diagnoses suggesting aeroallergen involvement 2
  • Potential for aeroallergens to alter clinical management 2, 1

Recommended Approach to EOE Management

First-Line Treatment

• Pharmacotherapy should be considered first-line for most patients:
  • Topical corticosteroids or PPIs are easier to implement than dietary restriction 1

Dietary Approaches (When Indicated)

1. Empiric Elimination Diet:

   • More effective than allergy test-directed diets 3
   • Step-up approach (2-4-6 food elimination) is preferred 1
   • Common triggers include milk, wheat/gluten, and egg 1

2. Elemental Diet:

   • Reserved for treatment-refractory cases 1
   • High efficacy but poor adherence and quality of life concerns

3. Allergy Test-Directed Diet:

   • Lowest histological remission rates compared to other dietary approaches 1, 4
   • Not recommended as primary approach 1

When Allergy Testing May Be Beneficial

Despite limitations for identifying food triggers, allergy testing may be beneficial in specific circumstances:

1. Concurrent Allergic Conditions:

   • A thorough evaluation by an allergist is recommended due to high rates of concurrent atopic diseases 2
   • Testing helps improve diagnosis and control of concurrent atopic diseases 2

2. Aeroallergen Sensitization:

   • Evaluation for aeroallergen sensitization may alter clinical management 2, 1
   • Seasonality of symptoms may correlate with aeroallergen exposure 2

3. Food Reintroduction Safety:

   • Medically supervised food reintroduction may be necessary for patients with:
     • Previous allergic reactions to foods
     • IgE-mediated sensitivity documented by SPT or serum food-specific IgE 2, 1
   • Patients with positive skin tests should be evaluated for immediate hypersensitivity reactions and prescribed epinephrine if indicated 2, 1

Monitoring and Response Evaluation

• Endoscopic evaluation with biopsies is required to confirm histologic improvement 1
• Clinical symptoms alone are insufficient to determine response 1
• Food triggers can only be definitively identified by documenting disease remission after elimination followed by symptom recurrence upon reintroduction 2, 1

Conclusion

While allergy testing has a role in evaluating concurrent allergic conditions and ensuring safe food reintroduction, it should not be the primary method for identifying food triggers in EOE management. Empiric elimination diets and pharmacotherapy remain more effective approaches for managing EOE.