Itchy red rash and 
periorbital swelling

Diagnosis of alpha-gal allergy should be made based on a detailed patient history that includes questions about the following: previous tick bite exposure; engagement in activities that would lead to tick bites, including biking, hunting, hiking, and gardening; foods that were eaten several hours before the onset of symptoms; physical exam; and lab tests, including immunoassays for IgE specific to alpha-gal, beef, and pork. Once the diagnosis has been made, management should include patient education about the avoidance of mammalian meat, treatment for an allergic reaction, and future avoidance of tick bites. 


It is important to review all possible sources of red meat. Patients should be educated that all beef, pork, lamb, and wild game are considered red meat. Only meat from fish or fowl should be ingested. Mammalian meat byproducts, including organ meats, gelatins, pork rinds, and jellied candy, need to be avoided as well. Management of anaphylaxis after unintended exposure should include antihistamines, epinephrine, and steroids. Patients should be prescribed an epinephrine pen injector, and the signs and symptoms of anaphylaxis and proper use of the injector should be reviewed. Patients should be advised to try an oral antihistamine such as diphenhydramine first and only to use the epinephrine if the reaction advances beyond pruritis and urticaria.¹


Avoidance of future tick bites is important. There is a strong likelihood that the acuity of allergic reactions might increase if patients continue to have additional exposure to tick bites.¹⁰ Areas known to be infested by ticks should be avoided during summer months due to peak tick activity occuring during that time.^11,12 If patients plan to be in areas with known tick infestations, they should wear long shirts tucked in and long pants with pant legs tucked into socks or boots. Use of clothing treated with permethrin and a chemical repellant containing N,N-Diethyl-meta-toluamide (DEET) is recommended as well. Patients should be sure to check their entire body afterwards and, if necessary, remove any ticks found to be attached. Removal of ticks should be done using fine-tipped tweezers and using a stable pressure while grabbing the tick as close to the mouth as possible.¹³ If patients are hesitant to remove the tick or if they were unsuccessful in their attempt to remove the tick, they would need to be seen by a provider to ensure complete tick removal. 


For many years, patients with peculiar complaints of delayed reactions after eating meat have been disregarded by many providers.⁸ Now equipped with this new information available about IgE specific to alpha-gal and the reactions it can cause, all providers who see patients with complaints of chronic urticaria or angioedema with an unidentified cause should have alpha-gal allergy included in the differential diagnosis. A detailed history is essential in the diagnosis of alpha-gal allergy and should include questions about possible tick-bite exposure, 24-hour diet recall, and timing related to the onset of symptoms after the last meal. Once the diagnosis has been made, treatment and management of the condition is straightforward. Most patients should be successful in avoiding recurrent episodes once equipped with the knowledge of how to avoid mammalian meat products and future tick bites.

Jennifer Spires, MSN, FNP-BC, is a nurse practitioner, practicing at Allergy and ENT Associates of Middle Tennessee in Hermitage.

From the August 01, 2015 Issue of Clinical Advisor