PATHOGENESIS OF FOOD ALLERGY The GI barrier

The development of food allergy requires an immunological reaction directed to a food antigen. This reaction may involve immunoglobulin E (IgE) or T lymphocytes (T cells) or some components of both IgE and T cells (mixed IgE/non-IgE reaction). Food allergy can manifest as cutaneous, respiratory, systemic (anaphylaxis) or gastrointestinal (GI) symptoms. The GI manifestations are listed in Table I. Discussion of all the GI manifestations of food allergy are beyond the scope of this review. Instead, the article focuses on some of the well-recognised clinical syndromes in food allergy: oral allergy syndrome (IgEmediated), the eosinophilic gastroenteropathies (mixed IgE/non-IgE-mediated), oesophagitis in particular and the food protein-induced disorders (T-cell mediated).