Epidemiological research on nonpeanut food allergies and allergies in diverse racial, ethnic, and socioeconomic groups is growing, and the impact of recommendations for early introduction is being felt in the clinic. Our expert panel discusses recent trends in the epidemiology of food allergies and how these trends impact treatment.

Our laboratory looks at public health numbers, and we see that approximately 1 in 13 children and approximately 1 in 10 adults have food allergies. In terms of trends, it is really interesting to see the disparities. Food allergies impact every racial and ethnic group. We are trying to better understand how this occurs and with which foods and to what degree of severity. We have noticed that the number of certain food allergies is higher in certain racial and ethnic groups. We see higher rates of shellfish and fin fish food allergies in the black population, occurrences of sesame allergies that are a little higher in the white population, and some increase in tree nut allergies in the Asian population. It is important to watch and understand these numbers because they can help you counsel your patients a little bit better.

The big thing that we have seen is that people in low socioeconomic status (SES) groups are often not getting to allergists. When you look at the Medicaid database, for example, the number of patients with food allergies seems really low, but that is most likely because they are not getting diagnosed by their generalist with a food allergy. I think that one of the big reasons for this, based on my experience with working in a Medicaid clinic, is a lot of these children may have had a reaction to a food and then they just stopped eating that food rather than finding out if the reaction is a true allergy.

But now, since we actually have treatments and better ways of diagnosing food allergies, it would be very important for these individuals to actually see an allergist and get a proper formal diagnosis. What we observe in patients in low SES groups is that a lot more time and money are being spent on Emergency Department visits and a lot less on allergist visits, special foods, and medications. This makes sense, but how do we help support them so that we can get them the proper diagnosis and the food they need to stay safe?

There are 2 trends that I have seen in my clinic. The first is related to the fact that we have been strongly recommending and encouraging the early introduction of peanuts and other foods as a means of trying to prevent food allergies. The good news is that it does seem like the message is getting out there and that more people are trying to do this. However, what that has meant for our clinic is that we are seeing younger and younger children with their first allergic reactions to peanuts. We have had patients as young as 6 or 7 months of age with new allergic reactions to peanuts and some other foods. We are trying to adjust to this and decide how best to care for patients who cannot tell us that they are not feeling well. From a therapeutics point of view, while multiple options have been approved by the US Food and Drug Administration (FDA) or are in developent, none of them have been studied in patients who are less than 1 year of age. So, this has created a new area for us to focus on.

The other trend that I have seen in our clinical practice is that, as we have moved away from considering tree nuts as a single food and have begun focusing on the individual nuts, cashew allergies appear to stand out among all the tree nut allergies as most prevalent. In addition, it seems that people may be more sensitive to cashews than to other tree nuts, meaning that they react to smaller amounts of the allergen even if they have lower skin test and laboratory levels. There is still a lot that we are trying to learn right now about determining the most common allergens and why people might get them, and I am hopeful that studies of birth cohorts going on here in the United States and abroad will be the key to help us better understand all of this.

We have seen increases in patients with IgE-mediated food allergies, along with other food allergy–driven conditions (with different immune mechanisms), including food protein–induced enterocolitis syndrome (FPIES) and eosinophilic esophagitis (EoE). FPIES affects mainly infants and toddlers, causing the development of severe delayed vomiting (with or without diarrhea) and lethargy to specific foods. The presentation of EoE varies per the age of the child, from gastroesophageal reflux symptoms and possible growth concerns in infants and toddlers, to abdominal pain in school-aged children, to food impaction and/or difficulty swallowing in adolescents and adults. Interestingly, milk is the most common cause of each condition, although children may outgrow IgE and FPIES reactions to milk. In addition, in our efforts to decrease IgE-mediated reactions in young children with early introduction to peanuts, we have seen FPIES reactions in some.