Eosinophilic esophagitis (EE) is a chronic inflammatory disease of the esophagus characterized by eosinophilic infiltration of the esophageal epithelium. The incidence of this diagnosis has been increasing, which is either secondary to increased prevalence or greater awareness of this condition. The disease typically affects young adult men, although it can be seen in any age or gender. Classically, adult patients present with long standing dysphagia to solids and recurrent food impactions. Infants can present with regurgitation, irritability, and failure to thrive. Often the patients have associated atopy, asthma, eczema, chronic rhinitis, or peripheral eosinophilia.
Classic imaging findings on barium esophagram are multiple, distinct, persistent, thin, concentric ring like indentations or areas of narrowing in the esophagus producing the characteristic "ringed esophagus" appearance. This has been called trachealization of the esophagus. These commonly involve the upper to mid-thoracic esophagus. An associated stricture is a common finding. A small-caliber esophagus with long segment, smooth narrowing with tapered margins can be another more subtle imaging finding.
Diagnosis is confirmed by EGD with biopsy. On endoscopy, ridges or furrows may be seen in the esophageal wall with ring-like indentations producing a "ringed esophagus" appearance. White exudates may also be present. Pathology demonstrates eosinophilic infiltration of the esophageal epithelium. Greater than 20 eosinophils per high power field must be present to make the diagnosis. This cut-off is to prevent a false-positive diagnosis of EE in the setting of reflux esophagitis, which can be associated with eosinophilicic infiltration, although it is usually less pronounced with 5-10 eosinophils per high power field. In addition, EE tends to involve the esophagus diffusely whereas reflux esophagitis tends to induce eosinophilic infiltration within the distal esophagus. Therefore, when a diagnosis of EE is suggested on barium swallow, a biopsy should be obtained in the proximal, mid, and distal esophagus. Differentiation of theses entities is crucial as treatment differs, with EE classically not responding to proton-pump inhibitors.
Although the exact cause is unknown, the relationship of eosinophilic infiltration and underlying atopic diseases have led many to believe that the disease develops as an inflammatory response to ingested food allergens; however, often the offending agent is never discovered and the disease can be idiopathic.
Treatment includes identification of any food allergens with appropriate dietary modification. Secondary therapy includes PO liquid corticosteroids, anti-histamines, leukotriene modifiers, and anti-interleukins. If stricture is present, mechanical dilatation may be needed. Prognosis tends to be excellent with appropriate treatment.