Eosinophilic esophagitis

Eosinophilic esophagitis
Micrograph showing eosinophilic esophagitis. H&E stain.
Classification and external resources
ICD-10	K20.0
ICD-9	530.13
eMedicine	article/1610470
MeSH	D057765

Endoscopic image of esophagus in a case of eosinophilic esophagitis. Concentric rings are termed trachealization of the esophagus.

The barium swallow of the esophagus on the left side shows multiple rings associated with eosinophilic esophagitis.

Eosinophilic esophagitis (eosinophilic oesophagitis), also known as allergic oesophagitis, is an allergic inflammatory condition of the esophagus that involves eosinophils, a type of white blood cell. Symptoms are swallowing difficulty, food impaction, and heartburn.^[1]

Eosinophilic esophagitis (EoE) was first described in children but also occurs in adults. The condition is not well understood, but food allergy may play a significant role.^[2] The treatment may consist of medication to suppress the immune response, but in severe cases it may be necessary to stretch the esophagus with an endoscopy procedure.

Signs and symptoms

EoE often presents with dysphagia (difficulty swallowing), food impaction, regurgitation or vomiting, and decreased appetite. In addition, young children with eosinophilic esophagitis may present with feeding difficulties and poor weight gain. It is more common in males, and affects both adults and children.^[1]

Pathophysiology

EoE is a relatively poorly understood disease of which awareness is rising.^[1][3]

At a tissue level, EoE is characterised by a dense infiltrate with white blood cells of the eosinophil type into the epithelial lining of the esophagus. This is thought to be an allergic reaction against ingested food, based on the important role eosinophils play in allergic reactions. Eosinophils are inflammatory cells that release a variety of chemical signals which inflame the surrounding esophageal tissue. This results in the signs and symptoms of pain, visible redness on endoscopy, and a natural history that may include stricturing.^[1]

Diagnosis

The diagnosis of EoE is typically made on the combination of symptoms and findings on diagnostic testing.^[1]

Prior to the development of the EE Diagnostic Panel, EoE could only be diagnosed if gastroesophageal reflux did not respond to a 6 week trial of twice-a-day high-dose proton-pump inhibitors (PPIs) or if a negative ambulatory pH study ruled out gastroesophageal reflux disease (GERD).^[3][4]

Endoscopically, ridges, furrows, or rings may be seen in the oesophageal wall. Sometimes, multiple rings may occur in the esophagus, leading to the term "corrugated esophagus" or "feline esophagus" due to similarity of the rings to the cat esophagus. Presence of white exudates in esophagus is also suggestive of the diagnosis.^[5] On biopsy taken at the time of endoscopy, numerous eosinophils can be seen in the superficial epithelium. A minimum of 15 eosinophils per high-power field are required to make the diagnosis. Eosinophilic inflammation is not limited to the oesophagus alone, and does extend though the whole gastrointestinal tract. Profoundly degranulated eosinophils may also be present, as may microabcesses and an expansion of the basal layer.^[1][6]

Radiologically, the term "ringed esophagus" has been used for the appearance of eosinophilic esophagitis on barium swallow studies to contrast with the appearance of transient transverse folds sometimes seen with esophageal reflux (termed "feline esophagus").^[7]

Treatment

Treatment strategies include dietary modification to exclude food allergens, medical therapy, and mechanical dilatation of the esophagus.

The initial approach to the disorder is often allergy evaluation in an attempt to identify the allergens in the diet or environment that may be triggering the condition. If the offending agent is found, the diet is modified so that these allergens are eliminated. There are cases, especially in children, where there are multiple food allergies involved. Some patients require an elemental diet through the use of a specialty formula. Sticking to this diet and drinking the required amount of formula can be difficult. The use of feeding tubes in these situations is often required.

First-line therapy is with swallowed liquid corticosteroids and other anti-inflammatories, including fluticasone, a topical viscous budesonide oral suspension. Patients with severe symptoms despite these interventions may require oral corticosteroids such as methylprednisolone. Other anti-inflammatory agents have also been trialled, including leukotriene antagonists such as montelukast, anti-interleukins such as the anti-IL-5 monoclonal antibody mepolizumab, and antihistamines such as loratadine. Unfortunately, these have shown little clinical benefit.

Mechanical dilatation may be considered in severe cases of EoE that have progressed to esophageal stricture or severe stenosis. Dilatation is accomplished by passing dilators through the mouth and down the esophagus to gently expand its diameter. As the esophagus of patients with EoE is rather thin and delicate, care is taken not to perforate the esophagus by overzealous dilatation.

Despite EoE being historically thought of as refractory to proton pump inhibitor treatment, there is some recent evidence to suggest a significant proportion of patients suffering from EoE achieving remission following PPI therapy.^[8]

Epidemiology

Many EoE patients suffer from concurrent autoimmune and allergic disease. This includes asthma^[1] and coeliac disease.^[9]

See also

• Eosinophilic gastroenteritis

References

External links

• CURED Foundation - Non-Profit for EGID Research
• American Partnership for Eosinophilic Disorders
• Families Affected By Eosinophilic Disorders
• Canadian Council of Eosinophilic Disorders
• Cincinnati Center for Eosinophilic Disorders
• Australian Support for Eosinophilic Disorders
• AEDESEO Asociación Espanola de Esofagitis Eosinofílica