We hope everyone has had a happy Memorial Day! For those of us who connect the summertime holidays with firing up the barbecue, let's talk about a medical condition we hope you never develop: alpha-gal allergy.
In this unusual food allergy, patients become sensitized to the carbohydrate group galactose-alpha-1,3-galactose ("alpha-gal") due to bites from lone star ticks (the tick has the carbohydrate in its gut and introduces it into the skin of those it bites). Because alpha gal is also found in red meat, patients can then develop allergic reactions after eating red meat.
Symptoms can include hives, swelling, respiratory difficultly, and GI upset, typically 3-6 hours following red meat consumption. Because this unusual allergy is to a carbohydrate that has slow and variable GI absorption, sometimes symptoms may not occur with small amounts of red meat consumption, making diagnosis more challenging. I enjoy caring for patients with this condition and have been featured in local and national media for my expertise (google "Robert Valet MD alpha gal allergy"), and would be happy to evaluate you if you are concerned about this condition.
Once diagnosed, treatment consists of avoidance of red meat, and more importantly, of additional lone star tick bites, which increase levels of antibodies to alpha gal and may help this allergy to persist. Ticks like to hang out on tall brush and drop off onto passing animals and people, so be careful in brush and inspect for ticks immediately upon returning indoors.