Many allergic conditions are limited to the GI tract.
Eosinophilic esophagitis is hard to miss esp if a few simple questions are asked eg dysphagia, eating slowly, cutting food into small bites etc.
Another food allergy presenting in the GI tract is FPIES- food protein induced enterocolitis.
Food poisoning is the earliest thought or viral gastroenteritis. For infants with a profound reaction with hypovolaemia FPIES should be thought of . As with eosinophilic esophagitis, these conditions are not IgE mediated so RAST tests are not diagnostic. Confirmation should be made with biopsy and elimination diets performed. Shellfish is a common cause .
Bradykinin mediated angioedema may present only with bowel angioedema and in 49 % is the only presentation.
The symptoms may be non specific such as cramping , distension, nausea, vomiting and diarrhoea and if any doubt a C4 test is a simple screening test.
Alpha gal sensitivity an IgE mediated anaphylactic reaction and most commonly occurs hours after eating red meat . The etiology is the bite of the lone star tick triggering sensitisation to cross reacting carbohydrate moieties. Anaphylactic episodes are hard to diagnose in the occasional red meat eater.
IgE to alpha gal is a commercially available test. Between 70 -90 % of
