Eosinophilic oesophagitis

Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease of the esophagus that affects children and young adults and manifests as difficulty swallowing (dysphagia), chest pain, and sometimes food becoming lodged in the esophagus. In children, esophagitis often manifests as vomiting, abdominal/chest pain, and refusal to eat. Patients often adapt their diet, avoid certain foods (bread, meat, rice), and eat more slowly. Chronic inflammation makes the esophagus stiffer, which can lead to narrowing (strictures). Therefore, to prevent this progression, long-term follow-up and maintenance treatment are indicated.

Gastroenterology consultation, recording of symptoms, recording of any allergies and atopic diseases, and assessment of nutritional status.

The diagnosis of EoE is based on the triad of symptoms of oesophageal dysfunction (particularly dysphagia), eosinophilic infiltration on oesophageal biopsies, and exclusion of other causes of oesophageal eosinophilia.

Investigations

• Gastroscopy (OGD) with biopsies: Essential examination that may reveal rings, furrows, a trachealised appearance, white exudates (microabscesses), or a fragile mucosa. At least 6 oesophageal biopsies (proximal and distal) are essential.
• Histology: Confirmation of the presence of at least 15 eosinophils per high-power field.
• Full blood count (FBC): To look for blood eosinophilia, which is often moderate.
• Allergy assessment: Not indicated as a first-line investigation in adult patients; skin tests (prick tests) or specific IgE measurements, often targeting milk, wheat, eggs or soya, are sometimes performed, although their sensitivity is limited.
• Barium oesophagram (TOGD or OED X-ray): Performed in cases of significant stenosis (narrowing) to map the lesions before endoscopic dilatation.

Treatment of EoE aims to reduce inflammation, relieve symptoms (dysphagia) and prevent fibrosis. First-line treatment is based on proton pump inhibitors (PPIs), topical corticosteroids (swallowed), or elimination diets, often continued long term. 

• PPIs: Often the first step in reducing inflammation, although their exact mechanism in EoE is not strictly related to reflux (intrinsic anti-inflammatory effect).
• Topical/local corticosteroids: Orodispersible budesonide is highly effective in treating inflammation and relieving symptoms; it is reimbursed in Belgium in cases of resistance to PPIs.
• Elimination diets: Removal of the most frequently implicated allergenic foods (milk, wheat, soya, eggs, tree nuts, fish and shellfish), ideally under dietary supervision. These diets are difficult to follow in adults and affect quality of life. For these reasons, an elimination diet excluding one or two allergens (milk, or milk and wheat) may be offered as first-line treatment.
• Biological therapies: New biological medicines targeting inflammation, such as dupilumab, are used when treatment with PPIs and budesonide fails. Dupilumab is reimbursed in Belgium for this indication.
• Oesophageal dilatation: Performed endoscopically in cases of significant narrowing (stricture) of the oesophagus.

Eosinophilic oesophagitis is a chronic disease requiring long-term medical follow-up to prevent complications, particularly fibrosis or strictures. Follow-up, supervised by a gastroenterologist, combines symptom assessment, endoscopies with biopsies, and management of treatments (PPIs, corticosteroids, biologic medication, diet).

• Regular medical follow-up: An annual consultation, or even one every two years, is recommended to assess treatment adherence and symptoms.
• Endoscopic monitoring: This is necessary because symptoms alone are not sufficient to assess disease activity. A follow-up endoscopy is necessary if treatment is modified (dose reduction or discontinuation of a medication) to confirm histological remission (a decrease in the number of eosinophils to < 15 per field).
• Maintenance treatments: prescribed to prevent recurrences. Most patients relapse when treatment is stopped, underscoring the importance of chronic management.
• Multidisciplinary approach: Follow-up often involves an allergist and a dietitian, particularly if an elimination diet is undertaken (milk, wheat, etc.).
• Monitoring for complications: Repeated endoscopies make it possible to monitor the development of strictures (narrowing of the oesophagus). 

The transition of patients treated and followed in paediatrics takes place during a gastroenterology consultation, in order to provide the necessary follow-up in adulthood.