Alpha-gal syndrome: A review for the dermatologist

Alpha-gal syndrome (AGS) is an allergy to red meatand other mammalian products due to immunoglobulin E (IgE) antibodies against the sugar moiety galactose-alpha-1,3-galactose (alpha-gal), which is acquired following tick bites. Clinically, AGS presents with urticaria, abdominal pain, nausea, and occasionally anaphylaxis, and has wide inter- and intra-personal variability. Because symptom onset is generally delayed by 2 to 6 hours after meat consumption, AGS can be easily confused with other causes of urticaria and anaphylaxis, such as chronic spontaneous urticaria (CSU) and mast cell activation syndrome (MCAS). Diagnosis relies on a combination of clinical history, positive alpha-gal IgE blood testing and improvement on a mammalian-restricted diet. Management of the syndrome centers primarily on avoidance of mammalian meats (and occasionally dairy and other products) as well as acute management of allergic symptoms. Counseling about tick avoidance measures is also important as AGS will wane over time in many patients. ( J Am Acad Dermatol 2023;89:750-7.)

Automated summary

Alpha-gal syndrome is an allergy to red meat and other mammalian products caused by immunoglobulin E antibodies acquired after tick bites. It presents with symptoms such as urticaria, abdominal pain, and nausea, which can be easily mistaken for other causes of urticaria and anaphylaxis. Diagnosis is based on clinical history, positive alpha-gal IgE blood testing, and improvement on a restricted diet. Treatment involves avoiding mammalian meats and managing acute allergic symptoms.