Food Allergy and Gastrointestinal Syndromes

Food allergy affects an estimated 8% of US children younger than 5 years and up to 10% of adults. The incidence of peanut allergy has quadrupled over the past decade in the US and appears to have increased globally as well. The pathophysiology of food reactions may be immunoglobulin E (IgE)-mediated, non-IgE-mediated, or mixed IgE- and non-IgE-mediated, and can affect the skin, gastrointestinal (GI) tract, respiratory tract, and/or cardiovascular system. Foods are major triggers of anaphylaxis in all ages. Increasing levels of serum food-specific IgE or skin-prick wheal diameters correlate with increasing probabilities of reactions. The double-blind, placebo-controlled food challenge remains the diagnostic gold standard. Food allergen avoidance requires education about reading ingredient labels, avoiding cross-contact, and obtaining safe meals. Managing food-induced anaphylaxis requires education about recognizing symptoms and prompt treatment with epinephrine. Early exposure to food through a disrupted skin barrier leads to allergic sensitization, whereas early oral exposure to peanut generally induces tolerance. Current food prevention strategies emphasize early oral exposure to peanut and egg as well as most other foods within the first year of life. Novel therapies utilize both allergen-specific and allergen-nonspecific approaches, with great potential for effective desensitization. The US Food and Drug Administration (FDA) approved the first immunotherapeutic vaccine for peanut in 2020.