One of the biggest fears of parents with children who have food allergies is life-threatening reactions, otherwise known as anaphylaxis. This fear can also manifest in parents of infants who don’t have food allergies, or who have never eaten potential allergens. That fear can be a barrier to the early introduction of peanut foods to prevent peanut allergies, which the National Institute of Allergy and Infectious Disease (NIAID) now recommends.  A recent study by researchers at a large children’s hospital in Chicago may help settle some fears about life-threatening reactions in infants by providing support for the idea that reactions are less severe among infants but may become more severe as children get older.

In the study, researchers reviewed the charts of patients 18 years old and younger who had been admitted for food-induced anaphylaxis (FIA) over two years. Three hundred fifty-seven cases were analyzed, including those of 47 infants (<12 months), 43 toddlers, 96 young children, and 171 school-aged children. Among the infants, the most common signs and symptoms were hives (94%) and gastrointestinal (GI) symptoms, especially vomiting (83%). Respiratory symptoms occurred in just 17% of infants and wheezing was present in 2% (only one subject). However, young children and school-age children were much more likely to develop oropharyngeal, throat swelling, or respiratory symptoms than infants. Cardiac symptoms were uncommon among all subjects. There were no deaths.

While any food can cause anaphylaxis, amongst infants in the study, egg and cow’s milk were the most common cause. These infant subjects had lower rates of anaphylaxis to peanuts and tree nuts as compared to the older children in the study. Thirteen percent of reactions in infants were to an unknown allergen. Eczema was significantly associated with allergic reactions, with more than one quarter of the study’s egg and cow’s milk allergic children and half of peanut allergic infants having a history of eczema.

The study supports the idea that the older a child gets, the more likely they are to have more severe reactions. Infants are less likely to have severe reactions than older children, although it can happen. This is good news for those concerned about anaphylaxis in infants during early introduction of peanut foods. The study authors do a great job summarizing how these results are helpful in understanding the safety of early introduction, “The early introduction of peanut-containing foods was based on the LEAP study, which focused on those with atopic dermatitis or history of food allergy. However, considering that most infants had less severe reactions and no atopic history, it is possible that all children could benefit from early introduction of allergenic foods.”

The information presented here is not a substitute for professional medical advice. Caregivers should contact their pediatrician with questions or concerns.

 Visit PreventPeanutAllergies.org for family-centered resources on early introduction of peanut foods.