Food Allergy
Basics
Food allergy is defined as an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food.
Description
- Hypersensitivity reaction related to certain food exposures; can involve IgE-mediated and non–IgE-mediated mechanisms
- System(s) affected: gastrointestinal (GI), heme/lymphatic/immunologic, pulmonary, skin/exocrine
- Synonym(s): allergic bowel disease; dietary protein sensitivity syndrome
Epidemiology
- Predominant age: all ages but more common in infants and children
- Predominant sex: male > female (2:1)
- Disproportionate impact on underserved and minority patients
Incidence
~2.5% of infants experience hypersensitivity reactions to cow’s milk in their 1st year of life (1)[B].
Prevalence
- Adults more commonly have allergies to shellfish (2%), peanuts (0.6%), tree nuts (0.5%), and fish (0.4%).
- 20% of children with peanut protein allergy may outgrow their sensitivity by school age.
Etiology and Pathophysiology
Allergic response triggered by immunologic mechanisms (e.g., IgE-mediated or non–IgE-mediated allergic responses) or non–immunologic-mediated mechanisms
- Any ingested substance can cause allergic reactions:
- Most commonly implicated foods include cow’s milk, egg whites, wheat, soy, peanuts, fish, tree nuts (e.g., walnut, cashew, and pecan), and shellfish.
- Several food dyes and additives may elicit non–IgE-mediated allergic-like reactions.
Genetics
- Although there is likely a heritable component to allergic diseases, the genetics are complex and not monogenic.
- Human leukocyte antigen (HLA) studies in peanut allergy have consistently failed to find associations.
- In families with a history of food hypersensitivity, the probability of food allergy in subsequent siblings may be as high as 50%.
Risk Factors
- Patients with allergic or atopic predisposition have increased risk of hypersensitivity reaction to food.
- Family history of food hypersensitivity
General Prevention
- High-risk infants fed peanut protein (6 g/week) have an 80% risk reduction in developing peanut allergy by age 5 years, and global infant feeding guidelines now recommend introducing peanut and other complementary foods starting at 5 months of age.
- In patients at risk for anaphylaxis, epinephrine autoinjectors should be readily available.
Commonly Associated Conditions
- Atopic dermatitis
- Eosinophilic esophagitis
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Citation
Domino, Frank J., et al., editors. "Food Allergy." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688871/all/Food_Allergy.
Food Allergy. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688871/all/Food_Allergy. Accessed June 2, 2023.
Food Allergy. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688871/all/Food_Allergy
Food Allergy [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 June 02]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688871/all/Food_Allergy.
* Article titles in AMA citation format should be in sentence-case
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T1 - Food Allergy
ID - 1688871
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ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688871/all/Food_Allergy
PB - Wolters Kluwer
ET - 27
DB - Medicine Central
DP - Unbound Medicine
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