Do You Have A Beef With The Lone Star Tick? Tick Bite Causes Meat Allergy

Autumn Bloom didn't think much of the tick that attached itself to her wrist when she took a walk in the woods. Her husband removed it with tweezers, and the bite didn't cause itching, inflammation, or redness. Just part of walking through tall grass on a hot summer day, Autumn thought.

Then about two months later, Autumn woke up gasping for breath about six hours after joining friends for a steak dinner. Painful, purple hives popped out all over body, and the swelling of her lips and in her throat made it almost impossible to breathe. Rushed to a hospital emergency room, Autumn had only minutes to live when she was given an injection of epinephrine and intravenous antihistamines.

A Severe Food Allergy

Autumn's doctors eventually figured out that her symptoms were caused by an allergy to red meat. But Autumn had eaten meat every day for years and years without ever having any problems. Why should a meat allergy, a potentially fatal meat allergy suddenly cause problems.

Like thousands of people in the eastern United States, Autumn developed a meat allergy after being bitten by a specific kind of tick, Amblyomma americanum, the lone star tick.

In recent years, it has also been found in Central American and Northern South America. The lone star tick prefers to live in underbrush under large trees.

The lone star tick can transmit a disease called STARI (Southern tick-associated rash illness), which has superficial symptoms similar to Lyme disease without the more severe symptoms. This tick does not transmit Lyme disease. However, a bite from the tick can sensitize the human immune system to a specific sugar that is found in meat, almost as if the tick wanted to keep any passing meat-producing animals for itself.

How the Lone Star Tick Primes the Immune System for Allergy

The immune system recognizes the microorganism that causes STARI by finding strands of a sugar called galactose-alpha-1,3-galactose, or alpha-gal for short. White blood cells are programmed to attack any cell they find coated with alpha-galactose, and usually the immune system "learns" how to attack the STARI microbe with a massive assault once it has won its battle against the infection.

See Also: Ten Tips for Avoiding and Removing Ticks

This new programming of the immune system protects the body against any infections from future lone star tick bites. Unfortunately, certain kinds of meat also contain large amounts of alpha-galactose. 

All of these foods contain small amounts of the alpha-galactose sugar. The immune system doesn't begin its attack until it senses the sugar, digested from meat, in the small intestine. At first, there may be diarrhea. Then as some of the alpha-galactose finds its way into the bloodstream, the immune system attacks it wherever it concentrates, especially in the lungs and in the skin.

How To Know If You Have A Meat Allergy, And What To Do About It

How can you know that you have a meat allergy?

Meat allergies are a group of allergic reactions known as IgE responses. They are relatively slow to produce symptoms, usually four to eight hours after exposure to the alpha-gal allergen. Only mammal meats contain alpha-gal; you won't get this kind of reaction after eating chicken or fish. Every bite with a lone star tick won't cause your immune system to become hyperreactive to meat; the tick itself has to have bitten another mammal before it bites you to trigger the allergic response.

Symptoms of Meat Allergy

The tick bites that cause meat allergies are usually memorable. The bite causes itching and/or swelling and persists while the body is building up an immune reaction to it. This initial reaction to the tick bite programs the immune system to react for meat.

It always takes several hours or more before it causes symptoms including any or all of the following:

• Nausea, vomiting, flatulence, and/or diarrhea.
• Rash or hives anywhere on the skin.
• Sneezing.
• Wheezing.
• Headaches.
• Asthma.
• Anaphylaxis, a life-threatening allergic reaction in which air passages are blocked by swelling of the lips, mouth, tongue, and/or lining of the throat.

Allergic reactions can also be triggered by cat dander, which contains the allergenic sugar alpha-gal, and by injection or insertion of products of animal origin, including some (but not all) vaccines. It is OK to get a vaccination with a product made by incubating a virus or a microbe in eggs, but not to get a vaccination of a product made with horse serums. In at least one case, a man who received a pig's valve to repair the mitral valve of his heart went into anaphylaxis after the procedure.

Meat allergies caused by sensitization after lone star tick bites are relatively rare in Texas, but much more common in the southeastern United States. In states such as Georgia, Florida, and the Carolinas, up to almost 50% of the population may have this problem.

What You Can Do About Meat Allergy

The obvious solution to a meat allergy is not to eat meat. Mild symptoms can be treated with Diphenhydramine (Benadryl), but anaphylactic reactions have to be treated with injections of epinephrine (adrenalin). If you have ever had an anaphylactic reaction after eating meat, you should have get a prescription Epi-Pen and keep it with you at all times, and other, responsible members of your household should know how to give you an injection if you are unable to give it to yourself. 

See Also: Severe Allergic Reactions to Meat Become Even More Common

If your household includes a cat, it may be essential to vacuum once or twice a week, cleaning upholstery as well as carpets and floors, and it may also be helpful to buy a HEPA air filter to remove cat dander from the air. Lone star tick-induced meat allergies cause milder symptoms with exposure to cat dander because the amounts of dander that get inside the body are relatively small, but chronic, hard to explain symptoms in people who give up meat may be caused by the dander.

Some doctors are finding that their patients improve over time. Eating large amounts of meat, however, will neve be a good idea, and prophylactic use of antihistamines, such as Benadryl, to prevent symptoms may always be a good idea once the condition has set in.