Alpha-Gal: What You Need to Know About This Allergy

Summertime is a great time to get out and enjoy our beautiful surroundings. In the densely-wooded Ozarks, however, ticks are numerous and can present serious health risks.

Phelps Health ENT (Ear, Nose and Throat) and Allergy Physician Brian Kriete, MD, routinely diagnoses two to three patients per week with alpha-gal syndrome (AGS) or allergy, also known as the tick bite meat allergy. Dr. Kriete answers frequently asked questions about this allergy.

“Alpha-gal syndrome is an allergy to a particular sugar typically following a tick bite,” said Dr. Kriete. “When the tick attaches, it injects this sugar into the bloodstream and causes an immune reaction leading to the production of antibodies to this sugar. Mammal meats have a similar sugar, and once the body is exposed to sugar in the meats, it leads to an allergic reaction called alpha-gal syndrome. Alpha-gal can be found in mammalian meats including pork, beef, rabbit, lamb, venison, etc., and products made from mammals, such as gelatin, cow’s milk and milk products.”

Is the Lone Star Tick to Blame?

Dr. Kriete said the lone star tick is the most likely culprit, but evidence does exist that other types of ticks can also transfer the alpha-gal allergy to red meat.

AGS is a relatively new diagnosis, first discovered at the University of Virginia in 2007.

“Alpha-gal is [also] an ingredient in the cancer drug Cetuximab, and it was causing allergic reactions in patients from certain geographic locations,” Dr. Kriete said. “No one knows for sure how long alpha-gal syndrome has been around, but it seems to be increasing in the US.”

There are reports that 1%–3% of the population in Missouri has AGS, Dr. Kriete noted. While he diagnoses the allergy more in adults, he sees pediatric patients for the allergy, too. Some evidence suggests that people with AB or B blood types may have a protective component against the allergy, according to a study at Washington University in St. Louis, Missouri.

“I first learned of the syndrome 4–5 years ago,” Dr. Kriete said. “I’m not sure if the syndrome is increasing in frequency, or if we are now better at diagnosing and recognizing this syndrome.”

Symptoms of AGS typically appear 2–6 hours after exposure, which is why the allergy is sometimes difficult to diagnose.

“AGS can be different from person-to-person,” said Dr. Kriete. “Symptoms can range from mild to life- threatening. People may not have a reaction after every exposure.”

What Are Alpha-Gal Symptoms?

Alpha-gal symptoms can include the following:

• Hives or an itchy rash
• Nausea and vomiting
• Diarrhea
• Cough, shortness of breath, difficulty breathing
• Drop in blood pressure
• Swelling of the lips, tongue, throat or eyelids
• Dizziness or lightheadedness
• Severe stomach pain

Patients with anaphylaxis (severe, potentially life-threatening allergic reactions), including lips, throat or tongue swelling; and/or a severe rash along with nausea and vomiting and light-headedness, should seek immediate medical care.

How Do I Know If I Have the Alpha-Gal Allergy?

AGS is typically diagnosed with a blood draw, and Phelps Health offers the appropriate testing. Patients can discuss testing with their primary care provider, or request a referral to Phelps Health ENT/Allergy if their provider is not comfortable ordering the testing.

As with any allergy test, Dr. Kriete added, the level of reaction or level on the labs does not always correlate with the degree of symptoms. That being said, higher levels on the blood test are typically seen in those with more severe reactions.

I’ve Been Diagnosed with AGS. What’s Next?

Depending on the severity of your symptoms, the diagnosis will typically mean a significant change in your diet, according to Dr. Kriete.

“All red and mammal meats will need to be avoided,” Dr. Kriete said. Some patients, but not all, will find they also need to avoid dairy products. A complete list of foods to avoid can be found on the Centers for Disease Control and Prevention’s (CDC) website.  The following foods do NOT contain alpha-gal: poultry (chicken, turkey, duck or quail); eggs; fish and seafood; and fruits and vegetables.

For most people, the symptoms are a mild nuisance, and there is no need to worry about cross-contamination. For patients with more severe reactions, however, cross-contamination can be a major concern.

How Do I Manage AGS?

“The symptoms of AGS are typically managed with a daily antihistamine like Benadryl, as well as its non-drowsy relatives (Zyrtec, Claritin, Allegra and Xyzal),” Dr. Kriete said. “An EpiPen is a wise investment, as symptoms can progress over time based on your dietary habits and further exposure to alpha-gal via [future] tick bites.”

Thankfully, AGS can improve in most patients by avoiding food allergens and further tick bites. Meeting with someone experienced in managing alpha-gal, like Dr. Kriete or another ENT/allergy provider, is important. Phelps Health gastroenterology providers also see patients for AGS, along with certain primary care providers.

Providers typically manage AGS with annual testing, and adjust dietary restrictions based on a patient’s current alpha-gal levels.

What Can I Do to Prevent AGS?

The CDC recommends the following prevention tips:

• Before you go outdoors:
  • Avoid grassy, brushy and wooded areas, where ticks may be found.
  • Treat clothing and gear with an insecticide, such as permethrin, or buy pre-treated items.
  • Use Environmental Protection Agency (EPA)-registered insect repellents.
• After you come indoors:
  • Check your clothing for ticks.
  • Shower and perform a thorough tick check.
• If you see an attached tick, remove it immediately.
• Take steps to prevent ticks on your pets and in your yard.