which included Virginia, Missouri, and tennessee. second, they were being treated with a cancer drug, cetuximab, which contained alpha-gal.
brush) or had taken ibuprofen, both of which are known to enhance an allergic reaction such as anaphylaxis and may have hastened onset of the reaction.
the third commonality among these patients? in addition to experiencing an allergic reaction shortly after their cancer drug was administered, these patients experienced a delayed allergic reaction hours after they ate red meat, such as beef, pork, or lamb.
although this patient lived in Minnesota where the lone star tick has not been found—yet—and although he was not taking the cancer drug that has been associated with this allergy, he did spend time in Virginia and had a history of allergic reactions to tick bites.
red meat contains alpha-gal. the reason for the delay in allergic reaction, unlike the faster onset of symptoms after administration of the cancer drug, is that alpha-gal in meat is attached to protein. the delayed reaction occurred because the ingested alpha-gal had to go through the intestines in order for digestion to release the alpha-gal from the protein. at that point, the patients’ bodies recognized it as an allergen and responded with anaphylaxis. Furthermore, these patients also had allergic reactions to the lone star tick, which is endemic in their region of the United states. a blood test was developed to detect allergy to alpha-gal. The final puzzle piece this test was performed on the patient’s blood and confirmed his allergy to alpha-gal. after further history-taking, he remembered having eaten steak or hamburger each day he experienced an anaphylactic reaction. the days his episodes occurred within two to four hours of eating beef were the days he was working vigorously (chopping wood, clearing
Lesson learned this case illustrates the importance of a thorough medical history. although the patient had told his story to multiple providers during the course of two years, none of them had made the connection between the patient’s time spent in a state known to contain the lone star tick (Virginia), his long history of tick bite reactions, and his red meat consumption the day of the reactions. all factors pointed to alpha-gal. if you or your family members vacation or have lived in the region of the country known to contain the lone star tick and have had hives or reactions to tick bites, be aware of this unusual allergy. check the centers for Disease control and Prevention website for states that have the lone star tick (www.cdc.gov/ticks/maps/lone_star_tick.html). Keep in mind that climate change may cause this tick to extend into additional states over time. Nancy L. Ott, MD, is board-certified in pediatrics and in adult and pediatric allergy and immunology. She is a senior associate consultant at the Mayo Clinic Children’s Center, Rochester.
Qualifies for FSA/HSA spending
December 2013 Minnesota HealtH care news
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