Mammalian meat allergy following tick bite

Mammalian meat allergy is a relatively recently recognised phenomenon, in which tick venom causes sensitisation to an allergen known as alpha-gal. The prevalence of mammalian meat allergy is uncertain. Symptoms often do not start for several months after a tick bite. They present as allergy of varying severity (anaphylaxis, angioedema, gut symptoms) generally 3 to 6 hours after ingesting meat, milk or other products containing alpha-gal (eg gelatin-coated medication)van Nunen, 2018. Consider the possibility of mammalian meat allergy in patients presenting with allergy as a delayed presentation after tick bite, or in tick-endemic areas even if a history of tick bite is not known. If a mammalian meat allergy is suspected, referral to an immunologist is recommended.

Management of confirmed mammalian meat allergy includes education of patients about avoidance of alpha-gal in mammalian meat and gelatin-containing foods, medicines and blood substitutesvan Nunen, 2018. See the Australian Society for Clinical Immunology and Allergy website for patient information on tick allergy and mammalian meat allergy.