The diagnosis of eosinophilic esophagitis is made from the clinical picture together with an esophageal biopsy, and treatment then aims to keep the inflammation in check over the long term.
Diagnosis
The gold-standard diagnosis for EoE is endoscopy with pathological study of the biopsy, which is characterised by:
- 15 or more eosinophils per high-power field (HPF), or about 60 eosinophils per mm²
- dilated intercellular space
- inflammation and fibrosis in the lamina propria
It is not adequate to make a diagnosis of EoE where there are isolated eosinophils in the biopsy without any clinical signs and symptoms.
In 2017 a structured histologic scoring system for EoE was established that grades 8 histological features and adds detail beyond the peak eosinophil count:
- eosinophil density
- basal zone hyperplasia
- eosinophil abscesses
- eosinophil surface layering
- dilated intercellular space
- surface epithelial alteration
- dyskeratotic epithelial cells
- lamina propria fibrosis
One important task during diagnosis is separating EoE from gastroesophageal reflux disease (GERD), which can be done using the number and distribution of eosinophils in the biopsy:
- fewer than 7 eosinophils per HPF points to GERD
- between 7 and 15 eosinophils per HPF points to a combination of GERD and food allergy
- more than 15 eosinophils per HPF points to EoE
- eosinophils only in the distal portion points to GERD
- eosinophils in both the proximal and distal esophagus points to EoE
No single count or distribution is completely reliable on its own, so the diagnosis also requires a clinical assessment of the other causes of esophageal eosinophilia.
Treatment and complications
Treatment of EoE, like the treatment of asthma, needs to be chronic and life-long: stopping it usually allows the inflammation to return. The main options are proton pump inhibitors; swallowed topical glucocorticosteroids such as budesonide or fluticasone, whose main adverse effect is local fungal or viral infection; elimination diets, from elemental to the empiric removal of common foods; and the biologic dupilumab, directed against the IL-4 receptor. Endoscopic dilation relieves a stricture but does not treat the inflammation underneath it.
If EoE is left untreated, progressive esophageal dysfunction and scarring can lead to:
- esophageal narrowing
- esophageal stricture
- narrow-caliber esophagus
- esophageal perforation
Because the non-esophageal EGIDs can occur alongside EoE, gastric and duodenal biopsies are taken when symptoms or endoscopic findings point to involvement, rather than as routine surveillance of the whole GI tract.