Eosinophilic gastroenteritis: epidemiology, diagnosis and management.

Eosinophilic gastroenteritis is a heterogeneous and uncommon disorder characterized by eosinophilic inflammation of the gastrointestinal tissues. The location and depth of infiltration determine its varied manifestations, and the latter is also the basis for the proposed classification into mucosal, muscular and serosal eosinophilic gastroenteritis. Abdominal pain, vomiting, and diarrhea are each present in nearly 50% of the patients, with some overlap. Peripheral eosinophilia is seen in approximately two-thirds of patients with eosinophilic gastroenteritis. It is now clear that eotaxin, a specific eosinophil chemoattractant, plays a pivotal role in the process of eosinophil production. The differential diagnosis of eosinophilic gastroenteritis in children includes parasitic infections, inflammatory bowel disease, connective tissue diseases, some malignancies and adverse effects of drugs. Eosinophilic gastroenteritis itself has been strongly associated with food allergies, and concomitant atopic diseases or a family history of allergies is elicited in about 70% of cases. The pediatric experience is unique with respect to recognition of distinctive entities such as allergic procto-colitis, almost exclusively seen in infants, and eosinophilic esophagitis being increasingly reported among children and young adults. The gold standard for diagnosis, usually demonstrated on endoscopic biopsies, is prominent tissue eosinophilia. However, the diagnosis may be obscured by the patchy nature of the disease, and muscular and serosal eosinophilic gastroenteritis subtypes. In the latter cases, full thickness biopsies would be indicated for a definitive diagnosis. There are many reports of successful treatment of eosinophilic gastroenteritis in children, using a variety of treatment regimens including elimination diets. Corticosteroids remain the most effective agents for controlling symptoms, but unfortunately the relapsing nature of the disease would mandate prolonged corticosteroid use. Reports of favorable responses to new leukotriene inhibitors in patients with eosinophilic gastroenteritis are encouraging; these responses should stimulate future research on the pathophysiology and management of eosinophilic gastroenteritis.