Continuing our series of posts, “Ask the Expert”, Dr. Dave Khan, Professor of Internal Medicine in the Division of Allergy and Immunology at UT Southwestern, summarizes the findings of a recently discovered allergy to certain meats.
Delayed meat anaphylaxis: A New Type of Food Allergy
“Within the last 7 years, an identification of a new type of food allergy has been discovered. The story begins with the realization that patients treated with the monoclonal antibody cetuximab, developed anaphylaxis with the first infusion. The majority of these reports were localized to the Southeast United States. A detailed investigation of the serum led to the identification of preexisting IgE antibodies to the oligosaccharide galactose-a-1,3 galactose (alpha-gal). Identification of IgE to alpha-gal led to the realization that IgE was associated with a novel form of food allergy. These patients reported urticaria or anaphylaxis starting 3-6 hours after eating beef, pork, or lamb. While cases of alpha-gal IgE have been reported in Europe and Australia, in the U.S., most cases have occurred in the Southeast. Scott Commins from the Univ. of Virginia has investigated this phenomenon and has identified that bites from the lone star tick are associated and likely causal of the alpha-gal IgE response. Recent reports from Commins’ group has confirmed the delayed nature of the reactions and basophil activation studies indicate that the relevant antigen does not enter the bloodstream until 3-5 hours after consumption of red meat, resulting in the delayed appearance of the allergic reaction. While less common in Texas (I have only seen one case), the discovery of this form of delayed food anaphylaxis has certainly reshaped how we evaluate patients with anaphylaxis.”
Thanks to Dr. Khan for contributing to the post!
Lone Star Tick
Credit: CDC Public Image Library