Plain language summary
Complementary feeding can be an exciting opportunity for your child to explore new foods and develop their palate. When trying allergenic foods for the first time, children should be monitored for the development of wheezing, hives, vomiting, and diarrhea. Children with eczema and allergic rhinitis are at high risk of having food allergies and may desire to try allergenic foods for the first time with a clinician present. Recent AAP guidelines recommend against delaying the introduction of allergenic foods, even with children at high risk of having food allergies.
Introduction
At around 6 months of age, complementary foods (or solids) are introduced to meet a baby’s nutritional demand.1 Introducing new foods to one’s infant can cause worry or be stressful for some parents because of concern about possible allergic reactions. With proper precautions, especially for infants at high risk of allergy, new foods can be introduced in a safe and healthy way that can even reduce the risk of food allergy development in the future.
What is complementary feeding?
Complementary feeding refers to the introduction of any foods or beverages in addition to, or to complement, breastmilk and/or formula to a child’s diet. Complementary foods are recommended to be introduced around 6 months of age.1 It is important to stick to nutrient-dense foods, such as fruits, vegetables, grains, meats, or other proteins, and to avoid foods or drinks with added sugar for children under the age of 2.2 At first, the amount of complementary foods consumed should not displace breastmilk/formula consumption since breastmilk/formula meets the majority of their nutritional needs. By 12 months, the majority of an infant’s nutritional demand should be met by complementary foods.3 However, mothers are encouraged to breastfeed for as long as they feel comfortable.
What is a food allergy?
A food allergy is an immune-mediated reaction that can be triggered after eating specific foods. When a food is consumed, proteins are broken down in the gastrointestinal tract into amino acids, peptides, and smaller proteins that the body can absorb. An immune reaction occurs when antibodies (usually IgE) are triggered by small proteins that were absorbed from a food.4 The release of IgE can cause a variety of symptoms such as hives, swelling, wheezing, coughing, sneezing, runny nose, vomiting, diarrhea, or hypotension within 2 hours of consuming the food allergen.4 Symptoms can range from mild to severe, including anaphylaxis, a systemic reaction with potentially life-threatening consequences. Allergic reactions in children typically present with gastrointestinal and skin-related symptoms. Additional information about complementary feeding guidelines can be found here: https://www.infantrisk.com/content/introducing-solid-foods.
The prevalence of food allergies in children in the United States is about 8%.5 Common food allergens are peanuts, tree nuts, wheat, soy, chicken eggs, shellfish, and cow’s milk, with peanuts being the most common in children. Certain allergens such as cow’s milk, egg, wheat, and soy are more likely to be outgrown while peanuts and tree nuts tend to be lifelong allergies. It is important to distinguish food allergies from food intolerances. Food allergies and food intolerances can have overlapping symptoms. However, allergies are immune-mediated while intolerances are triggered by non-immune causes, for example, enzyme deficiencies (i.e. lactose intolerance). There can also be food allergies mediated by other immune processes that do not utilize IgE. These non-IgE-mediated food allergies have delayed reactions from more than two hours through the next day and symptoms include vomiting, bloody stools, and dermatitis.5 Examples include Celiac disease and food protein-induced enterocolitis syndrome.
Diagnosis of allergy
A diagnosis can be made based on clinical history. Because food allergy symptoms can vary widely, an accurate history of what the child has eaten and when symptoms began is important for identifying patterns leading to a diagnosis. While clinical history is usually sufficient for diagnosis, it is not guaranteed. Allergy testing is typically performed in two ways: a skin pinprick test, where a small amount of a specific antigen is placed under the skin and observed for the formation of a wheal, or a blood test that measures the level of IgE antibodies.6 Home test kits are available on the market for allergy testing, but healthcare providers do not recommend them. Testing an infant for food allergies is not currently recommended before the consumption of the food and should be focused on specific foods rather than a wide range of foods as this can make testing less clear. For this reason, at-home allergy skin pinprick tests that test for an array of allergies are discouraged. Importantly, positive allergy tests alone do not necessarily equate to a food allergy; however, in combination with clinical history, these are useful tools.
Children with atopic diseases such as eczema, asthma, and allergic rhinitis (allergic reaction causing sneezing or congestion) are at a higher risk of developing food allergies. Severe eczema is the most important risk factor of the three.5 Additionally, a child who already has an egg allergy is at increased risk of developing a peanut allergy. Contrary to common belief, a family history of food allergies is not a useful predictor of food allergy development.
How to introduce potential food allergens
Previous guidance from medical associations advised waiting until after the first year of life to introduce common allergenic foods. However, more recent guidelines from the American Academy of Pediatrics (AAP) do not recommend delaying giving allergenic foods; delaying allergenic foods shows no benefit for the prevention of food allergies.7 Early introduction of allergens, such as peanuts, may even prevent food allergy development. Introduction to foods such as peanuts and cooked eggs may begin after the introduction of non-allergenic complementary foods. Complementary foods should not be given prior to 4 months of age. When starting complementary foods, it is important to do so as a single ingredient (e.g. carrots or avocados) and to wait 1 to 2 days before introducing another new food.7 This allows for sufficient time to observe and easy identification of the food that caused the problem.
Special precautions may be practiced when introducing common food allergens. Keeping dye-free diphenhydramine on hand is recommended if your child begins showing mild signs of an allergic reaction such as itchy nose, sneezing, itchy mouth, a few hives, and mild nausea. Ask the pediatrician for an appropriate dose before initiating the food.
For high-risk children, peanut products may be given under the supervision of a clinician. It is appropriate to call your pediatrician first before seeking care if symptoms are mild. Call 911 if your child exhibits severe symptoms of an allergic reaction within 2 hours of eating an allergenic food. Severe symptoms include: shortness of breath, wheezing, hoarse voice, sudden cough, trouble swallowing, sudden drooling, or slurred speech.8 Seek medical care at the ER if your child shows signs of hives all over the body, face swelling, vomiting, and stomach cramps within 2 hours of eating an allergenic food.
Prevention of food allergies
Breastfeeding has the potential to lessen the severity of atopic disorders but does not have a clear role in preventing food allergy. The AAP states that exclusive breastfeeding for the first 3 to 4 months of life protects a child from developing eczema during the first two years of life.8 Additionally, continued breastfeeding beyond the first 3-4 months of life can reduce the risk of asthma and asthma-related symptoms such as wheezing.
There is no clear evidence that breastfeeding reduces the severity or frequency of food allergy.9, 10 Food allergens consumed by a lactating parent may result in very small amounts of allergen in the breast milk but rarely cause a reaction. Additionally, there is insufficient evidence of a relationship between maternal diet during pregnancy and food allergy in the infant.
Early introduction of peanut-containing products may provide long-term benefits against peanut allergies. Children with severe eczema and/or an egg allergy should be given peanut products between 4-6 months of age to reduce the likelihood of peanut allergy development long-term. In fact, in a landmark study (LEAP), children ages 4-10 months were divided into two categories: those who ate 2 grams of peanut protein three times a week and those who abstained from eating peanut butter. The study demonstrated that early peanut introduction was able to reduce the risk of allergy development by 80% in these high-risk children.9 A follow-up study (LEAP-ON) in 2015 demonstrated that these lower rates of allergy development were sustained throughout childhood even if peanuts were not consumed again after exposure during infancy.11,12
Food products, like Ready. Set. Food and Lil Mixins have been developed to provide children with an all-in-one product that can expose children to a wide range of allergens such as peanuts, eggs, and milk. These products claim to reduce the risk of children developing food allergies. However, the FDA has submitted warning letters to these companies, claiming that the doses of allergens in their products are much smaller than what was proven to be effective in the LEAP trial.13 Because products tend to combine allergens, if a child reacts, it will be unclear which of the foods triggered the reaction. If you would like to expose your child to similar levels of peanut protein that were used in the LEAP trial, a similar dose is 2 teaspoons of peanut butter three times per week.14
Conclusion
Complementary feeding can be an exciting opportunity for your child to explore new foods and develop their palate. When trying allergenic foods for the first time, children should be monitored for the development of wheezing, hives, vomiting, and diarrhea.4 Children with eczema and allergic rhinitis are at high risk of having food allergies and may desire to try allergenic foods for the first time with a clinician present.7 Recent AAP guidelines recommend against delaying the introduction of allergenic foods, even with children at high risk of having food allergies. In fact, the introduction of allergenic foods after 4 months of age may even decrease the risk of the development of food allergies.7 We recommend discussing any concerns you may have with your pediatrician, particularly if your infant has eczema, asthma, or allergic rhinitis, and is, thus, at higher risk for food allergies. Discussion prior to 6 months will allow you time to develop a plan for safely introducing complementary foods.
Navigating shopping with allergies
While allergies can be scary and make shopping more challenging, there are many resources available to make things less difficult for families. If it is determined that your child is allergic or intolerant to one of the major allergens, there are several apps available to help make grocery shopping easier. Delivery grocery stores, like Thrive, allow you to filter for specific diets choices (dairy free, gluten, vegan, etc. for $60/yr). The Fig app ($50/yr) allows you to scan products at the grocery store to determine if there are allergens present. Apps like mySymptoms help users connect the dots between logged foods and symptoms with probabilities and printable reports for $10. We encourage you to talk with your allergist and pediatrician to determine if there are local or specific resources that they recommend.
Original content by:
Mariel Schroeder, MS3
Christine D. Garner, PhD, RD, CLC
Edited by:
Kaytlin Krutsch, PharmD, BCPS
Nichole Campbell, MSN, APRN, NP-C
References
1. American Academy of Pediatrics. Starting Solid Foods. Updated August 12, 2022. Accessed October 10, 2023. https://www.healthychildren.org/English/ages-stages/baby/feeding-nutrition/Pages/Starting-Solid-Foods.aspx
2. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. Available at https://www.dietaryguidelines.gov/.
3. Center for Disease Control and Prevention. Infant and Toddler Nutrition. Accessed October 16, 2023. https://www.cdc.gov/nutrition/InfantandToddlerNutrition/index.html
4. American Academy of Pediatrics. Infant Allergies and Food Sensitivities. Healthychildren.org. Accessed October 12, 2023. https://www.healthychildren.org/English/ages-stages/baby/breastfeeding/Pages/Infant-Allergies-and-Food-Sensitivities.aspx
5. Venter C, Groetch M, James JM, Sicherer SH. Chapter 2 Immunoglobulin E-Mediated Food Allergies. In: Health Professional’s Guide to Nutrition Management of Food Allergies. Chicago, IL: Academy of Nutrition and Dietetics; 2023.
6.Sicherer SH, Wood RA. Allergy testing in childhood: using allergen-specific IgE tests. Pediatrics. Jan 2012;129(1):193-7. doi:10.1542/peds.2011-2382
7. Amanda Cox M. When can I start giving my baby peanut butter? Accessed October 12, 2023. https://www.healthychildren.org/English/tips-tools/ask-the-pediatrician/Pages/When-can-I-start-giving-my-baby-peanut-butter.aspx
7. American Academy of Pediatrics. Anaphylaxis Symptom Checker. Healthychildren.org. Accessed January 29, 2024. https://healthychildren.org/English/tips-tools/Symptom-Checker/IFrame/Pages/symptomviewer.aspx?symptom=Food+Allergy#:~:text=Symptoms%20of%20Food%20Allergies&text=Life%2Dthreatening%20allergic%20reactions%20also,of%20eating%20a%20certain%20food.
8. American Academy of Pediatrics. AAP Clinical Report Highlights Early Introduction of Peanut-based Foods to Prevent Allergies. Accessed October 12, 2023. https://www.healthychildren.org/English/news/Pages/Early-Introduction-of-Peanut-based-Foods-to-Prevent-Allergies.aspx
9. Stoody EE, Spahn JM, Casavale KO. The Pregnancy and Birth to 24 Months Project: a series of systematic reviews on diet and health. The American Journal of Clinical Nutrition. 2019-03-01 2019;109(Supplement_1):685S-697S. doi:10.1093/ajcn/nqy372
10. Du Toit G, Roberts G, Sayre PH, et al. Identifying infants at high risk of peanut allergy: The Learning Early About Peanut Allergy (LEAP) screening study. Journal of Allergy and Clinical Immunology. 2013-01-01 2013;131(1):135-143.e12. doi:10.1016/j.jaci.2012.09.0151
11. Du Toit G, Sayre PH, Roberts G, et al. Effect of Avoidance on Peanut Allergy after Early Peanut Consumption. New England Journal of Medicine. 2016-04-14 2016;374(15):1435-1443. doi:10.1056/nejmoa1514209
12. Du Toit G, Roberts G, Sayre PH, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. Feb 26 2015;372(9):803-13. doi:10.1056/NEJMoa1414850
13. FDA. Before Brands Inc Warning Letter. October 9th, 2020. Accessed January 29th, 2024. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/brands-inc-607630-10092020
14. Fleischer DM, Chan ES, Venter C, Spergel JM, Abrams EM, Stukus D, Groetch M, Shaker M, Greenhawt M. A Consensus Approach to the Primary Prevention of Food Allergy Through Nutrition: Guidance from the American Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; and the Canadian Society for Allergy and Clinical Immunology. J Allergy Clin Immunol Pract. 2021 Jan;9(1):22-43.e4. doi: 10.1016/j.jaip.2020.11.002. Epub 2020
