GI Presentations of Allergic and Immunologic Diseases

Medical maxims abound: What's common is common, but you're also more likely to encounter an uncommon presentation of a common disease than a common presentation of an uncommon one. With that in mind, this viewpoint is devoted to both the former and the latter. The inspiration was a patient of mine whose digestive symptoms improved after elimination of alpha gal allergens, supported by corresponding lab studies. It's anecdotal, but as you read, you'll see that this has been described by others — and so, consider this piece "food for thought."

Many allergic conditions are limited to the gastrointestinal (GI) tract (eg, eosinophilic esophagitis or eosinophilic gastroenteritis). The presentation of eosinophilic esophagitis is hard to miss, especially if routine screening is performed at any visit. A few simple questions (eg, dysphagia, eating slowly, cutting food into small bites) usually suffices. The latter can be harder to identify but still is "on the radar" of the astute practicing allergist.

Another food allergy presenting with purely GI symptoms is food protein–induced enterocolitis syndrome (FPIES). The first event may not be suspected to be allergic; viral gastroenteritis or food poisoningis usually the first thought, especially in adult patients. For infants with a profound reaction with hypovolemia, FPIES should be included in the differential diagnosis.