Food allergy and eosinophilic gastroenteritis and colitis

Eosinophilic gastroenteritis (EGE) and eosinophilic colitis (ECO) are two forms of chronic inflammatory disorders of the gastrointestinal tract characterized by eosinophil accumulation in the mucosa or in deeper layers of the gastrointestinal wall and associated with atopic disease. The eosinophilic gastrointestinal diseases broadened the spectrum of atopic gastrointestinal disorders formerly restricted to food allergy manifestating at the gastrointestinal mucosa. Their awareness increased enormously; therefore, we will review current knowledge about atopic gastrointestinal diseases for the allergologist.

Major attention will be drawn to the differential diagnosis, because symptoms of atopic gastrointestinal diseases frequently mimic those of other chronic inflammatory bowel diseases (IBDs) or irritable bowel syndrome (IBS), although the diseases are distinct in their histopathology, gene expression signature, response to therapy, and association with allergies. The pathogenesis of EGE and ECO will be described that involves environmental and genetic factors, particularly food antigens and expression level of interleukin (IL)-5 and selective chemokines.

Understanding symptoms and pathology of such disease is the basis of a rational treatment based on reduced exposure to offending food antigens as well as anti-inflammatory therapy. Atopic gastrointestinal diseases are in many cases reversible; however, chronic treatment is often necessary to prevent relapse.