There remains a limited number of therapeutic options with EoE. Dietary therapy can be effective as well as burdensome. A closer look at dietary treatment effectiveness was recently published (J Allergy Clin Immunol 2012; 129: 1570-8 –thanks to Seth Marcus for alerting me to this article).
Due to eligibility requirements, only 98 patients of an initial 513 met criteria. The findings from this study may be difficult to generalize because of the following:
- Highly selected patient population
- Retrospective study. Dietary therapy was NOT chosen randomly.
- Study originates from a specialized center (Cincinnati) which attracts atypical cases of EoE
That being said, the study asks some important questions. What is the remission rate for skin test-directed elimination diet in comparison to six food group elimination diet (SFED) and to an elemental diet? The SFED actually composed two groups (in my opinion, this is a significant flaw in the study design & has a limiting effect on the conclusions). The ‘classical’ SFED (42% or 11/26) eliminated the six most common food groups (milk, soy, wheat, egg, nuts, fish/shellfish) whereas a ‘modified’ SFED (58% or 15/26) combined the classical SFED with foods eliciting positive skin-testing.
Some of the authors terminology:
- Complete remission: 1 or fewer eosinophils/hpf
- Partial remission: 2-5 eos/hpf
- Partial resolution: 6-14 eos/hpf
- Remission: <15 eos/hpf
- Non-remission: >15 eos/hpf
Skin prick tests (SPFs) were performed to as many as 62 foods and 11 environmental allergens and graded 0-4. 0 equated to negative control & 4 equated to histamine control -all interpreted at 15 minutes after placement.
Atopy patch tests (APTs) were interpreted at 48 hours with scoring between 0-4. A score of 2 indicated “erythematous with generalized induration.” Any score of 2 or higher was considered positive.
Food reintroduction process: “Food reintroductions were initiated only when the peak eosinophil count was less than 15 eosinophils/hpf. If symptoms occurred after reintroduction of a food, patients were instructed to discontinue that food, wait approximately 10 to 14 days, and then reintroduce another food…. A food reintroduction was considered successful if no symptoms were reported and the postpeak eosinophil count was less than 15 eosinophils/hpf.”
Why were so many patients excluded? The main causes were 181 patients did not meet strict EoE criteria, 122 patients received glucocorticoids, and 52 patients had another eosinophilia-associated condition; less common reasons included patient age >21, being part of a separate drug trial, obvious noncompliance, different diet regimen, and not having 2 consecutive EGDs separated by dietary intervention.
How many endoscopies are needed for dietary therapy? In this study, the average patient had 8.5 EGDs at Cincinnati. The greatest number of EGDs took place among patients assigned to an elemental diet (average >11); these patients also had a longer followup period compared to the other two groups: 2.9 years compared with 1.1 for SFED and 2.1 for directed diet.
- All three diets resulted in improvement in eosinophil count.
- Overall Remission rates: 96% elemental, 81% SFED, 65% directed diet
- Complete Remission rates: 59% elemental, 39% SFED, 30% directed diet
One interesting set of data is in Table 4. This gives the pass rate for various foods with single and multiple food reintroductions. Milk for example had a pass rate of 35% among the 17 patients who had this as a single food reintroduction. The values ranged from a low pass rate of 29% for strawberries to a high pass rate of 78% for cocoa and 75% for pork. Soy, eggs, and wheat all hovered near 60% pass rate.
Conclusions by authors:
1. “SFED is no less successful than directed diet and consistent with unreliability of skin testing …Our data…undermine the value of skin test-directed dietary management. ” This is due to the fact that the disease mechanism is not an IgE-mediated disease (skin testing primarily detects IgE-mediated allergens).
2. Elemental diet is superior at inducing histologic remission. However, “multiple studies indicate that adherence is inversely related to the number of foods eliminated.”
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