Exercise-induced anaphylaxis after consumption of red meat in a patient with IgE antibodies specific for galactose-alpha-1,3-galactose

Abstract

In 2009, Commins and Platts-Mills reported a “novel form of delayed anaphylaxis to red meat” related to serum IgE antibodies to the oligosaccharide galactose-alpha 1,3-galactose (alpha-gal) caused by a tick bite from the lone star tick, Amblyomma americanum. It is now recognized that IgE antibody to alpha-gal is common in the southeastern United States and is associated with 2 forms of anaphylaxis: immediate-onset anaphylaxis during first exposure to intravenous cetuximab and delayed-onset anaphylaxis after ingestion of mammalian meat. This information has added a new aspect to the care of patients who might otherwise have been diagnosed with idiopathic anaphylaxis, which can be quite frustrating for patients and clinicians alike. In cases of mammalian meat allergy due to alphagal, we are now able to provide patients with the answer to the frequently asked question, “What can I do to prevent these reactions?” Not only can we provide them with a diagnosis, but in so doing we improve their quality of life and provide them with the knowledge of what to avoid to prevent these potentially life-threatening reactions. Although more cases have been recognized and diagnosed since the initial report of anaphylaxis to mammalian meat due to alpha-gal, there are multiple factors that can prevent or delay diagnosis. As Tripathi et al noted, “the lack of enthusiasm for this syndrome could be easily understood because its features run counter to many established teachings about food allergy and anaphylaxis.” It is taught that food allergy reactions typically begin within 1 to 2 hours of consumption of the offending food and with every ingestion. However, in alpha-galeinduced mammal meat allergy, the reaction is delayed, and in most cases occurs 3 to 6 hours after consuming beef, pork, venison, or lamb. Many patients do not have positive skin prick test results to meat extracts. Therefore, intradermal testing to meat is now being done. Patients also may be unaware of or fail to recall previous tick bites. In addition, patients may not experience reactions with every ingestion of mammalian meat, which may be due to the type, processing, dose, and/or preparation of the mammalian meat product. It should be noted that the severity of reactions may worsen over time with continued tick bites. The most commonly reported symptom was itching. To add to the growing body of knowledge regarding mammalian meat allergy due to alpha-gal, we are presenting a novel case of exercise-induced anaphylaxis (EIA) after ingestion of red meat in a patient with IgE antibodies to alpha-gal. In this case, the reactions also occurred more rapidly than typical alphagal reactions, happening in 1 to 1/2 hours instead of 3 to 6 hours.