Definition:

• Alpha-gal syndrome is a type of food allergy to red meat and other products made from mammals. In the United States, the condition most often begins when a Lone Star tick bites someone. The bite transmits a sugar molecule called alpha-gal into the person’s body. In some people, this triggers an immune system reaction that later produces mild to severe allergic reactions to red meat, such as beef, pork lamb, or other mammal products.
• The Lone Star tick is found predominantly in the southeastern United States, and most cases of alpha-gal syndrome occur in this region.
• People with antibodies related to alpha-gal syndrome can have allergic reactions to the cancer drug cetuximab (Erbitux).

Signs and symptoms

• Hives, itching, or itchy, scaly skin (eczema)
• Swelling of the lips, face, tongue and throat, or other body parts
• Wheezing or shortness of breath
• A runny nose
• Stomach pain, diarrhea, nausea or vomiting
• Sneezing
• Headaches
• A severe, potentially deadly allergic reaction that restricts breathing (anaphylaxis)
• Although studies based on a rheumatoid arthritis (RA) mouse model have suggested a crucial role for Gal-1 in inflammation, clinical data are lacking.

Tests

• Blood test. A blood test can confirm and measure the amount of alpha-gal antibodies in your bloodstream.  
• Allergy skin test.

Treatment

• As with any food allergy, alpha-gal syndrome treatment involves avoiding the foods that cause your reaction. Always check the ingredient labels on store-bought foods to make sure they don’t contain red meat or meat-based ingredients, such as beef, pork, lamb, organ meats, or gelatins. Check soup stock cubes, gravy packages, and flavor ingredients in prepackaged products. Ask your doctor or allergist for a list of foods to avoid, including meat extracts used in flavoring. The names of some ingredients make them difficult to recognize as meat-based.
• Use extra caution when you eat at restaurants and social gatherings. Many people don’t understand the seriousness of an allergic food reaction, and few realize meat allergies even exist. Even a small amount of red meat can cause a severe reaction.
• For a severe allergic reaction, you may need an emergency injection of epinephrine and a visit to the emergency room. Many people with allergies carry an epinephrine autoinjector (EpiPen, Auvi-Q, others). This device is a syringe and concealed needle that injects a single dose of medication when pressed against the thigh. Once you’ve been diagnosed with alpha-gal syndrome, your doctor or allergist likely will prescribe an epinephrine autoinjector.

Symptoms of alpha-gal syndrome may lessen or even disappear over time if you don’t get any more bites from ticks that carry alpha-gal. Some people with this condition have been able to eat red meat and other mammal products again after one to two years without additional bites.