Culprit avoidance prevents food-dependent exercise-induced allergic reactions

Marc Riedl, MD

This systematic literature review largely reinforces what is already known about the clinical features and management of food-dependent exercise-induced anaphylaxis (FDEIA). What is significant about the publication is the comprehensive inclusion of 722 patients from 231 studies/reports, which provides strong data to support the findings.

In fact, the described clinical presentation, causative foods, diagnostic test results and management are very much consistent with my own experience in evaluating and managing this condition.

The study findings highlight the importance of taking a careful clinical history when anaphylaxis, urticaria and angioedema are involved. Because 91% of patients with FDEIA have a single causative food, identifying this food by history allows for appropriate testing, which is highly sensitive at confirming the condition. The data here also demonstrate that subsequent management strategies of causative food avoidance prior to exercise and medications are highly successful.

Very little is known about the pathophysiology or mechanisms causing FDEIA, though, so more translational research will be needed to better understand the root causes of this condition.

Jennifer Bufford, MS, CRQM, CCRP, CCRC, and Bruce Roberts, PhD

FDEIA, a subtype of exercise-induced anaphylaxis, is an uncommon form of anaphylaxis that typically occurs with exercise 2 to 4 hours after the ingestion of a particular food trigger. Anaphylaxis does not occur following ingestion of the food in the absence of exercise. Wheat, shellfish and nuts are noted as the most common food triggers.

Although researchers first coined the term FDEIA in 1983, the condition remains underdiagnosed and underreported. The reported prevalence has ranged from less than 0.001% to 0.017% worldwide for all food.

As stated in the article, “this is the first systematic review of more than 200 studies reporting on more than 700 patients with food-dependent exercise-induced allergic reactions, including FDEIA, provides comprehensive insights into their clinical manifestations, time course, culprit foods and exercises, augmenting factors, comorbidities, treatments and treatment outcomes. Somewhat surprisingly, food-dependent exercise-induced reactions in one of six patients are limited to wheals and/or angioedema. These patients are commonly reported to have FDEIA even though they do not develop anaphylaxis.”

The Food Allergy Research & Education (FARE) patient registry database does not shed light on this subject, though, so FARE does not have a basis for comparing these results to the experience of its members.

Because FDEIA is predominantly a clinical diagnosis, a thorough history is key. A careful medical history and identification of the events precipitating the reaction and the involved cofactors must be considered when gathering the individual’s history. A proper diagnosis of FDEIA will help prevent unnecessary food and exercise limitations and provide a patient with FDEIA an adaptable lifestyle.

The authors suggest the likelihood of experiencing FDEIA might be reduced if individuals avoid consumption of culprit foods prior to exercise. However, this will only be possible if individuals are able to pinpoint the nature of the culprit food.

In the absence of definite data, individuals may wish to employ caution in consumption of common trigger foods such as wheat, shellfish or nuts if they intend to exercise thereafter and have had a known history of FDEIA.

Clifford Bassett, MD, FAAAAI, FACAAI

The review of findings of varied clinical dermatologic and other presentations is helpful to get a better scope of these data from three dozen publications. Most allergists to my knowledge do not see large numbers of patients with FDEIA, and the 722 patients in this review are helpful in looking at aggregate data with more bandwidth.

The authors help to clarify some of the pieces of an often-confounding diagnostic challenge, as far as the number of foods that trigger reactions as well as the timing of their ingestion and the patients’ exercise.

It was surprising to learn from the data that more than 90% of these patients reacted to only a single food. I also believe, although it was not specifically mentioned, that the total cost of rendering diagnostics, treatment and follow-up for FDEIA would be relevant given the climate of cost-effectiveness.

As far as the “on-demand” treatment goes, I do not see how an additional long-acting antihistamine prescribed along with a relatively short-acting medication could be useful in those individuals with short-lived, intermittent and persistent symptoms.

It also is not entirely surprising to see a preponderance of atopic patients within the study population. Further, it is important to note the normal baseline tryptase among 15 of the study’s patients and the elevated total IgE across all patients.