For a little while, I’ve meant to complete a post on the EoE guidelines published last fall (J Allergy Clin Immunol 2011; 128: 3-20). This article, based on the input of 33 physicians with EoE expertise, provides a lot of depth to this unfolding area in pediatric gastroenterology.
Diagnosis of EoE. The authors caution that this diagnosis is not a histologic diagnosis as a number of entities can cause esophageal eosinophilia; at the same time, a minimum number of eosinophils, 15/hpf, is a necessary diagnostic threshold. A small number of patients may have EoE with fewer than 15/hpf, including PPI-responsive EoE, inadequate biopsy sampling, seasonal variation, or partial treatment (eg. patient on corticosteroids).
How many biopsies? In one cited study in the article, 2, 3, and 6 biopsies had sensitivity of 84%, 97%, and 100% respectively. Endoscopic biopsies remain the only reliable diagnostic test.
Why are there a subset of PPI-responsive EoE patients? Potential explanations include improvement in immune-activation after healing of esophageal mucosa, inherent anti-inflammatory property of PPIs, or due to pitfalls in current diagnostic testing. Due to recognition of this disorder, pH testing may be needed in many patients with suspected EoE. Even still, the authors note that “PPI responsiveness or diagnostic testing (pH monitoring) might not adequately distinguish GERD and EoE.”
How useful are genotypic features? Clinical use of genotypes is not feasible at this time. However, it is anticipated that esophageal gene expression will emerge as one way to differentiate EoE from other conditions and to determine optimal treatments.
What type of allergy evaluation? The majority of EoE patients have concurrent atopic diseases, including rhinitis, asthma, and eczema. Thorough evaluation by an allergist (or immunologist) is recommended. Specific recommendations: skin prick testing (SPT), serum IgE for immediate-type food allergy. Atopy patch testing (APT) has high negative predictive values, >90%, except for milk which is ~50%. APT needs to “be standardized and validated.”
Biomarkers? “Insufficient evidence to support any peripheral marker” including cytokines, and IgE (total).
Treatment –PPI: PPIs are useful to distinguish GERD as well as PPI-responsive EoE from EoE requiring other treatments. They also help with symptomatic treatment in some patients who have secondary GERD. Recommended dose in children 1 mg/kg/dose BID.
Treatment –Dietary: Three dietary regimens have potential effectiveness: 1) selective food diet based on allergy testing, 2) dietary restriction of the most likely food antigens (eg. six food group diet elimination) and 3) strict amino acid based diet. Tolerance of foods that have been shown previously to provoke EoE is unlikely to develop in the majority of EoE patients.
Treatment –Corticosteroids: Corticosteroids are effective but when discontinued EoE almost always recurs. Systemic corticosteroids can be particularly useful when severe dysphagia is present. With severe endoscopic findings, a course of corticosteroids may help reduce the need for dilatation or lessen the risk. Long-term use of systemic steroids is not recommended. Topical steroids should be considered in all patients with EoE. Recommended doses are given.
- For fluticasone: 88-440 μg 2-4 times per day (max 880 μg BID)
- For budesonide: 1mg daily (<10 y) and 2 mg daily (≥10 y)
Treatment –Dilation: Dilation can provide relief of dysphagia. In most cases, medical or dietary therapy should be attempted prior to use of dilation. Goal of 15-18 mm. Practical advice (not validated in studies): Limit dilation progression per session to 3 mm or less after resistance has been encountered.
Treatment –Alternatives: Cromolyn, leukotriene receptor antagonists, or immunosuppressive agents (eg azathioprine, 6-mercaptopurine) are “not recommended.”
Complications: Perforations (spontaneous & procedure-related), food impactions, strictures, and narrow caliber esophagus. There has not been evidence of an increased esophageal cancer risk in EoE patients to date.
Unresolved issues: Despite the extensive consensus on many of these issues, the conclusions inform the reader of how far we need to go. Some of the unresolved questions include such basic problems:
- “Importance of treating asymptomatic patients”
- “Natural history of EoE and rates and predictive indexes of complications”
- “Accuracy of skin prick and patch testing”
- “Optimal end points of treatment”
Previous related blog posts:
The undiscovered country
Eosinophilic Esophagitis -Six Food Group Diet
Practical information on EoE for families: