From the Guidelines
Alpha-gal syndrome is a food allergy that requires complete avoidance of all mammalian meat and products, including organ meats, gelatin, and some dairy products to prevent potentially life-threatening anaphylaxis and other symptoms. The key features of alpha-gal syndrome include delayed allergic reactions to red meat and other mammalian products, which can occur 3-6 hours after consumption, with symptoms ranging from hives, itching, and gastrointestinal distress to anaphylaxis 1. This condition is triggered by the development of IgE antibodies against the carbohydrate galactose-alpha-1,3-galactose (alpha-gal), which is present in most mammals but not in humans or other primates.
Key Features of Alpha-Gal Syndrome
- Delayed allergic reactions to red meat and other mammalian products
- Symptoms can range from hives, itching, and gastrointestinal distress to anaphylaxis
- Reactions typically occur 3-6 hours after consumption of mammalian meat
- Triggered by the development of IgE antibodies against the carbohydrate galactose-alpha-1,3-galactose (alpha-gal)
Dietary Restrictions
- Complete avoidance of all mammalian meat and products, including:
- Organ meats
- Gelatin
- Some dairy products, particularly those with high fat content such as ice cream, cream, and cream cheese 1
- Fish, seafood, turkey, chicken, and other fowl are acceptable for patients with alpha-gal syndrome
- Patients should also be cautious about medications, vaccines, and medical devices that may contain mammalian-derived ingredients such as gelatin or glycerin
Management
- Carrying emergency epinephrine (such as an EpiPen) for accidental exposures
- Careful label reading
- Informing healthcare providers about the allergy before procedures or when receiving medications
- Avoiding further tick bites to reduce the risk of sensitization and worsening reactions 1
From the Research
Key Features of Alpha-Gal Syndrome
- Alpha-gal syndrome (AGS) is an allergy to "red meat" and other mammalian products due to immunoglobulin E (IgE) antibodies against the sugar moiety galactose-alpha-1,3-galactose (alpha-gal) 2
- Clinically, AGS presents with urticaria, abdominal pain, nausea, and occasionally anaphylaxis, with wide inter- and intra-personal variability 2
- Symptom onset is generally delayed by 2 to 6 hours after meat consumption, which can lead to confusion with other causes of urticaria and anaphylaxis 2
Dietary Restrictions and Avoidance
- Management of AGS centers primarily on avoidance of mammalian meats (and occasionally dairy and other products) 2
- Patients with AGS should also avoid products containing gelatin of bovine or porcine origin, as they can induce basophil activation and increase the risk of anaphylaxis 3
- Gelatin-containing vaccines, such as those for varicella, zoster, measles, mumps, and rubella, should be administered with caution or avoided in patients with AGS 3
Treatment and Management
- Diagnosis relies on a combination of clinical history, positive alpha-gal IgE blood testing, and improvement on a mammalian-restricted diet 2
- Antihistamines, mast cell stabilizers, and complementary and alternative therapies, such as auricular acupuncture, may be used to manage AGS symptoms 4, 5
- Oral immunotherapy and biological products are emerging as potential treatments for AGS, but more research is needed to fully understand their effectiveness 5
Perioperative Implications
- Alpha-gal syndrome has significant implications for patients undergoing surgery, as mammalian products are commonly used in the operating room and can trigger severe allergic reactions 6
- A multidisciplinary approach is necessary to screen and prevent exposure to mammalian products in patients with AGS, and to prevent harm in this vulnerable population 6