What are the diagnostic criteria and treatment options for eosinophilic esophagitis?

Diagnosis of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is diagnosed when a patient has symptoms of esophageal dysfunction and at least 15 eosinophils per high-power field (or ~60 eosinophils/mm²) on esophageal biopsy, after a comprehensive assessment has ruled out other disorders that could cause or contribute to esophageal eosinophilia. 1

Diagnostic Criteria

Clinical Presentation

• Symptoms of esophageal dysfunction are required for diagnosis, including dysphagia, food impaction, chest pain, or feeding difficulties 1
• Concomitant atopic conditions (asthma, allergic rhinitis, eczema) increase suspicion for EoE 1, 2
• Symptoms may vary by age: adults typically present with dysphagia and food impaction, while children may present with feeding difficulties, vomiting, or failure to thrive 3

Endoscopic Findings

• Characteristic endoscopic features include rings, furrows, white exudates, edema, strictures, narrowing, and crepe-paper mucosa 1, 4
• However, a normal-appearing esophagus does not exclude EoE; up to 10% of patients may have normal endoscopic findings 5
• The EoE Endoscopic Reference Score (EREFS) provides standardized assessment of endoscopic findings 4

Histological Criteria

• At least 15 eosinophils per high-power field (or ~60 eosinophils/mm²) in at least one esophageal biopsy specimen 1
• Multiple biopsies (at least six) should be taken from different anatomical sites within the esophagus to increase diagnostic yield 1
• Additional histological features supporting the diagnosis include:
  • Basal cell hyperplasia
  • Eosinophil microabscesses
  • Eosinophil layering
  • Eosinophil degranulation
  • Subepithelial sclerosis
  • Spongiosis (epithelial edema) 1

Exclusion of Other Causes

• Assessment for non-EoE disorders that cause or potentially contribute to esophageal eosinophilia is required 1
• Conditions to exclude include:
  • Gastroesophageal reflux disease (GERD)
  • Hypereosinophilic syndrome
  • Achalasia
  • Crohn's disease
  • Infections
  • Connective tissue disorders
  • Drug hypersensitivity reactions 1, 6

Important Diagnostic Considerations

PPI Therapy and Diagnosis

• PPI-responsive esophageal eosinophilia is now considered part of the EoE spectrum, not a separate entity 1
• A PPI trial is no longer required for diagnosis of EoE 1
• EoE and GERD are not mutually exclusive and can coexist in the same patient 1

Biopsy Protocol

• At least six biopsies should be taken from different anatomical sites within the esophagus 1
• Biopsies should be obtained regardless of endoscopic appearance 5
• Gastric and duodenal biopsies should be obtained if clinically indicated by symptoms or endoscopic findings 1

Histological Response Assessment

• After treatment initiation, follow-up endoscopy with biopsy is recommended to assess response 1
• Histological remission is defined as <15 eosinophils per 0.3 mm² 1, 2
• Symptoms may not always correlate with histological activity 1, 7

Treatment Options

Pharmacological Therapy

• Proton pump inhibitors (PPIs) are effective in inducing histological and clinical remission 1
  • Should be given twice daily for 8-12 weeks before assessing response 1
• Topical steroids (fluticasone, budesonide) are effective for inducing histological and clinical remission 1, 3
  • Clinical and histological relapse is high after withdrawal of topical steroid treatment 1

Dietary Therapy

• Elimination diets are effective in achieving clinico-histological remission 1
• Options include:
  • Six-food elimination diet (higher histological remission rates but lower compliance) 1
  • Two or four food elimination diets 1
  • Elemental diets (high efficacy but low compliance) 1
• Support from an experienced dietitian is strongly recommended throughout elimination and reintroduction process 1

Endoscopic Therapy

• Endoscopic dilation is safe and effective for patients with fibrostenotic disease 1, 8
• Can be performed using either balloon or bougie dilators 1
• Clinical outcomes are better when combined with anti-inflammatory therapy 1

Pitfalls and Caveats

• Allergy testing to foods (skin prick, specific IgE, patch testing) is not recommended for choosing dietary restriction therapy 1
• Early diagnosis and treatment may prevent long-term complications of fibrosis and strictures 1
• Endoscopists can underestimate the frequency of strictures and narrow lumen esophagus 1
• Esophageal physiological testing should be considered in patients with ongoing dysphagia despite histological remission 1
• EoE is the most common cause of spontaneous perforation of the esophagus 1