Potential Development of Tolerance After Dietary Therapy
Once a food trigger is identified in EoE, the mainstay of therapy is continued avoidance of that particular food. There have not been systematic studies evaluating recurrent food challenges and the possible development of tolerance over time. One of the first studies to address this issue was by Leung et al., who performed a retrospective review of their pediatric EoE patients who were known to have milk as their food trigger. They identified 15 patients who had subsequently reintroduced baked milk back into their diets for at least 6 weeks, and 11 of them (73%) had maintained histologic remission despite the reintroduction of baked milk products. The study did not mention the precise time when reintroduction of baked milk products occurred in these patients. Despite this limitation, this study suggests that, over time, some patients with cow's milk-induced EoE may be able to tolerate milk reintroduction in the form of baked milk, which would allow a considerable broadening of the diet.
Another study exploring this concept was performed by Lucendo et al. in adults. This group evaluated the use of a cow's milk-based hydrolyzed formula in patients with cow's milk-induced EoE. Seventeen adult patients with cow's milk-induced EoE were administered this formula over a period of 8 weeks, and repeat endoscopy was performed. At that time, 88% of patients maintained histologic remission as defined by less than 15 eos/hpf. This study suggests that some patients with EoE triggered by a cow's milk protein may tolerate reintroduction of milk in this reduced antigenic state. While these formulas are not readily available, this study does provide insight into the pathophysiologic mechanisms of food allergy that trigger EoE, and suggests that some patients are tolerant to less antigenic preparations of their food triggers.