What causes eosinophilic esophagitis and how is it treated?

Causes and Treatment of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder of the esophagus primarily triggered by food antigens, representing a unique form of non-IgE mediated food allergy that requires ongoing treatment to prevent progression to fibrostenotic disease.

Causes of Eosinophilic Esophagitis

• EoE is primarily triggered and maintained by food antigens, representing a unique form of non-IgE mediated food allergy that largely depends on delayed, cell-mediated hypersensitivity 1, 2
• The most common food triggers identified in patients with EoE are milk, wheat/gluten, and egg, which are involved in the majority of cases from the United States, Spain, and Australia 2
• Environmental allergens may also play a role in triggering EoE in some patients 3
• The condition involves chronic esophageal inflammation that, if left untreated, can lead to esophageal remodeling and stricture formation 1

First-Line Treatment Options

Pharmacological Therapy

• Proton pump inhibitors (PPIs) are effective first-line therapy for inducing histological and clinical remission in patients with EoE 4, 5
• PPIs should be given twice daily for at least 8-12 weeks prior to assessment of histological response (20-40 mg twice daily for adults; 1 mg/kg per dose twice daily for children) 4
• In patients who achieve histological response, PPI therapy appears effective in maintaining remission 4
• The anti-inflammatory effects of PPIs in EoE are independent from their gastric acid secretion inhibition 1

Topical Corticosteroids

• Topical steroids are highly effective for inducing histological and clinical remission in EoE 5
• Formulations originally designed for asthma therapy (fluticasone or budesonide) can be swallowed rather than inhaled 1
• Newer effervescent orodispersible tablets and viscose formulations designed to coat the esophageal mucosa provide increased effectiveness at reduced doses 1
• Esophageal candidiasis is a potential side effect of topical corticosteroid therapy 4

Dietary Therapy Options

• Elimination diets are effective in achieving clinico-histological remission in both adults and pediatric patients with EoE 4, 2

• Three main dietary approaches exist:

  1. Elemental diet: Exclusive feeding with amino acid-based formula (highly effective but poor compliance) 4
  2. Empiric elimination diets: Removing common food triggers without prior testing 4, 2
  3. Allergy testing-directed elimination: Less effective, especially in adults 2, 6

• A step-up approach is recommended, starting with less restrictive diets:

  • Two-food elimination diet (milk and wheat/gluten) 7, 8
  • If unsuccessful, progress to four-food elimination diet (adding egg and legumes/soy) 7, 8
  • Six-food elimination diet (milk, wheat, egg, soy, nuts, and fish/seafood) has higher histological remission rates but lower compliance 4, 2

• Support from an experienced dietitian throughout both the elimination and reintroduction process is strongly recommended 4, 5

• Allergy testing to foods (skin prick, specific IgE, and patch testing) is not recommended for choosing dietary restriction therapy for EoE 4

Management of Fibrostenotic Disease

• Endoscopic dilation is effective in improving symptoms in patients with fibrostenotic disease due to EoE 4, 5
• 87% of patients experience clinical improvement with esophageal dilation 4
• Dilation should be considered an acute and adjuvant rather than an isolated chronic management strategy 4
• Clinical outcomes are better if therapeutic dilation is combined with effective anti-inflammatory therapy with topical steroids or other treatments 5
• Complications are rare but include perforation (0.4%), hospitalization (1.2%), and significant gastrointestinal hemorrhage (0.1%) 4

Monitoring and Follow-up

• After initiation of therapy, endoscopy with biopsy while on treatment is recommended to assess response, as symptoms may not always correlate with histological activity 4, 5
• At least six biopsies should be taken from different anatomical sites within the esophagus for diagnosis and follow-up 4
• Histological remission is defined as a maximum eosinophil count <15 eosinophils/0.3 mm² 4
• If treatments are stopped, disease activity (symptomatic, endoscopic, and histologic) has a high chance of recurring 4

Treatment Algorithm

1. Initial approach: Start with PPI therapy (twice daily for 8-12 weeks) 4
2. If PPI fails: Consider topical corticosteroids or dietary therapy 5
3. For dietary approach: Begin with two-food elimination diet (milk and wheat), progressing to four-food and six-food elimination if needed 7, 8
4. For fibrostenotic disease: Add endoscopic dilation to anti-inflammatory therapy 4, 5
5. Maintenance therapy: Continue effective treatment to prevent disease progression 1
6. Follow-up: Perform endoscopy with biopsies to assess treatment response 4

Common Pitfalls and Caveats

• Symptoms may not correlate with histological activity, necessitating endoscopic assessment of treatment response 4, 5
• Allergy testing has poor predictive value for identifying food triggers in EoE 4, 2
• Long-term untreated disease can lead to esophageal remodeling and stricture formation 1
• Prolonged elimination diets may impact quality of life and nutrition, requiring dietitian support 4, 5
• There is a small risk of developing de novo IgE-mediated food allergies after prolonged elimination diets 7