Bitten By A Tick, She Can't Have Red Meat Any More

Sharing from Jan McFarland:

“I am trying to find information on beef allergy. In about 1990 I began to get very ill after eating beef, it took a couple years to narrow down the severe reaction to specifically beef. It worsened over the years, I do not dare eat ANY beef or liquid from beef. Now I hear about the lone star tick that may be the cause so I am researching on this. Would like to know more and if there is treatment ( I ate beef for my first 40 years then suddenly could not). Can you provide information on this?”

Thanks to Jan for raising this topic.

What is Red Meat Allergy?

For about two decades, clinics have seen severe allergy cases after eating red meat – beef, lamb, etc. Researchers have proved that it comes from the immune system’s reaction to a molecule commonly known as alpha-gal.

Alpha-gal is a small carbohydrate, naturally existing in most mammals. However, monkeys, apes, and humans don’t make alpha-gal on their own.

Human immune systems are primed to see any alpha-gal in the bloodstream as an invader. The immune systems make antibodies to fend off the invader, thus an allergic reaction forms.

Lone Star Ticks

Like Jan, people who developed severe allergic reaction on alpha-gal had been eating red meat for decades and nothing was wrong. What made things different?

It’s not until recent years that researchers linked the red meat alpha-gal allergy to a specific type of tick – the lone star tick.

Lone star ticks are named for the white splotch on the backs of adult females, they are most common in southern and eastern states. However, their geographic distribution is expanding, their habitat now extends from the Southeast almost all the way to the Canadian border—which means more people may encounter them.

Lone star ticks don’t cause Lyme disease. But along with spreading the alpha-gal allergy, they can also transmit the bacteria that cause another disease called ehrlichiosis. Ehrlichiosis can cause fever, muscle pain, nausea, vomiting, and, rarely, rash. It’s fatal in about 1.8 percent of cases, according to the Centers for Disease Control and Prevention, although it can be treated with antibiotics.

It’s not entirely clear to scientists why a bite from a tick can cause a person to develop an allergy to red meat, and the allergy doesn’t happen to everyone who’s bitten.

Allergic Symptoms

Typically, with an alpha-gal allergy, a reaction doesn’t start until several hours after eating red meat. This is different from common allergic reactions to food which occur immediately after exposure, within a few minutes.

Early signs of anaphylaxis may include a metallic taste, burning, tingling, or itching of the tongue or mouth, headache, and feelings of fear or confusion. A reaction can progress quickly, and severe symptoms include throat swelling, difficulty breathing, vomiting, diarrhea, and more.


If you think you may be experiencing anaphylaxis, even if you’ve never had an allergic reaction before, you should call 911.

If you experience trouble breathing, wheezing, or throat swelling, you should use an epinephrine auto-injector if you have one.

When the reaction is under control, it’s highly recommended that you confirm with your doctor if it’s an alpha-gal reaction caused by tick bite.

There’s no cure for red meat allergy, so if you’re diagnosed, you’ll need to avoid the foods that trigger a reaction. That could include various kinds of red meats, and even sometimes milk.

For some people, when they avoid all future bites from lone star ticks, their levels of the antibodies to alpha-gal may diminish, and the allergy could subside. However, there aren’t enough data to analyze how common this is.

Protect Yourself

The lone star ticks are much more aggressive than other common types of ticks in the U.S. , meaning if you’re bitten by a tick in the lone star tick territory, it’s highly possibly by a lone star tick. Although the vast majority in this country and elsewhere who get bitten by ticks don’t develop alpha-gal allergy, you can take reasonable precautions to protect yourself from ticks.

  1. Wear an effective bug spray

Consumer Reports’ insect repellent testing has found that some products containing 15 to 30 percent deet, 20 percent picaridin, or 30 percent oil of lemon eucalyptus can provide the best protection.

  1. Dress for the occasion

Wear long pants and long sleeves, and tuck your pants into your socks.

  1. Keep your yard unfriendly to ticks

Keep your lawn grass cut, since ticks love tall grasses. Clean up brush and weeds, too.

  1. Check yourself for ticks

Check yourself at the end of every day if you’ve been out in their territory. If you find them on you, remove them properly. When you take care with the clothes, make sure to use a hot dryer to kill any ticks that may be clinging on, and leave your shoes outside in the sun.


Aug, 2019

A research team in UVA’s Department of Microbiology, Immunology and Cancer Biology has found that people with the meat allergy have a distinctive form of immune cells known as B cells, and they have them in great numbers. These white blood cells produce antibodies that release chemicals that cause the allergic reaction to meat.

The researchers will keep studying on the B cells to try to figure out a possible treatment.

People who develop the allergy in response to the bite of the Lone Star tick often have to give up eating mammalian meat, including beef, pork, and lamb entirely.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.