Adult Onset Food Allergies: What Are They?

Happy National Nut Day, everyone!

While I usually love any excuse to celebrate a food holiday, this is one that I will have to sit out on. Similar to many other Americans with food allergies, I developed an adult onset allergy around age 22 – following both my mother and sister who developed the same allergy at a similar age.

According to a study led by pediatrician Dr. Ruchi Gupta in 2017, over half of American adults can report to having developed at least one food allergy after age 18. The most common allergies developed as an adult include shellfish, peanuts, and tree nuts (Smith 2017). When most p

eople think of allergies, they picture anaphylaxis – itching, difficulty breathing or swallowing, coughing, chestpain, vomiting, etc. This is certainly a reaction that is still seen with adults and children. However, allergies and intolerances can manifest in a number of different ways that can be less noticeable than anaphylaxis. The following are other symptoms which can appear in an allergic reaction:

  • Itchy mouth
  • Swelling of the lips, tongue, and throat
  • Vomiting, diarrhea, abdominal cramps and pain
  • Hives (welts), itchy rashes
  • Persistent eczema
  • Tightening of the throat, trouble breathing, wheezing, coughing
  • Sneezing, hoarseness, nasal congestion
  • Drop in blood pressure, fainting, weak pulse (FAACT 2017)

While it’s still unclear exactly what causes the onset of an adult food allergy, studies vary in reasons from genetics to environment to a change in the immune system. As these allergies can develop at any time (for me, my realization came on a day where I ate way too many handfuls of Peanut M&Ms), it is important to pay attention to your body’s cues and notice any differences in how you feel after eating.

Additionally, understanding and accommodating those who may develop these allergies is important as well. While working with a client as an RD or even just chatting with a friend, try to avoid dismissing a reaction they describe to you regarding a food. Eliminating and reintroducing foods to the diet can be an effective way of narrowing down a potential allergy. And of course, in the case of more serious reactions, always seek medical attention.


FAACT. Adults with Food Allergies. Food Allergy & Anaphylaxis Connection Team. Accessed October 19, 2017.

Smith N. Half of American Adults Growing into Food Allergies, Finds Study. Allergic Living. Published August 30, 2017. Accessed October 19, 2017.

Meet the Author

Kate Egan

Kate Egan

Kate Egan is a new RDN working for Noom as a virtual health coach. She completed her dietetic intern and MBA at Dominican University in River Forest, IL.She graduated with a BS in Dietetics and a minor in Child and Family Studies from University of Wisconsin – Stevens Point in 2015. In addition to blogging for CAND, she has also blogged for Student Scoop, the student blog portion of AND’s Food and Nutrition Magazine.
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