Diagnosis, Natural History and Treatment of Eosinophilic Enteritis: a Review.

PURPOSE OF REVIEW: To review recent findings regarding eosinophilic enteritis, including epidemiology, pathogenesis, natural history, and treatment.

RECENT FINDINGS: A 2017 population-based study using a US healthcare system database identified 1820 patients with a diagnosis of eosinophilic enteritis among 35,826,830 individuals. The majority of patients with eosinophilic enteritis in this study were women (57.7%), Caucasian (77.5%), and adults (> 18 years of age) (83.5%). The overall prevalence of eosinophilic enteritis was estimated at 5.1/100,000 persons. Eosinophilic enteritis, also known as eosinophilic gastroenteritis, is a rare primary eosinophilic gastrointestinal disorder (EGID) of unknown etiology characterized by the presence of an intense eosinophilic infiltrate on histopathological examination of the intestinal mucosa. The etiology of eosinophilic enteritis remains unknown. However, there is evidence to support the role of allergens in the pathogenesis of this disorder, as children and adults with EGIDs often have positive skin testing to food allergens and a family history of allergic diseases. Recent studies unraveling the role of IgE-mediated but also delayed Th2-type responses have provided insight into the pathogenesis of this disease. Eosinophilic enteritis causes a wide array of gastrointestinal symptoms such as abdominal pain, diarrhea, nausea, vomiting, bloating, or ascites, and its diagnosis requires a high degree of clinical likelihood, given the nonspecific clinical presentation and physical examination findings. Oral corticosteroids are considered to be the mainstay of treatment and are generally used for a short period with good response rates. Antihistamine drugs and sodium cromoglycate have also been used to treat patients with eosinophilic enteritis. Preliminary studies have demonstrated the potential benefit of biological therapies targeting the eosinophilic pathway such as mepolizumab, an anti-IL5 antibody, or omalizumab, an anti-IgE monoclonal antibody. Eosinophilic enteritis is generally considered to be a benign disease without relapse, but up to 50% of patients may present a more complex natural history characterized by unpredictable relapses and a chronic course.