Alpha-gal symptoms: What are the early signs of alpha-gal syndrome?

Overview: What does alpha-gal syndrome (AGS) feel like?

Alpha-gal syndrome (AGS) is a red meat allergy that starts with a tick bite. Specifically, it’s an allergy to a carbohydrate or sugar molecule called alpha-gal (galactose-alpha-1, 3-galactose), which is found in red (mammalian) meat, dairy, and other products derived from mammals. The lone star tick transmits the alpha-gal molecule through its saliva.

The body develops an alpha-gal allergy as a response to alpha-gal, which causes the immune system to produce alpha-gal antibodies. After ingesting a food containing alpha-gal, symptoms usually begin within three to eight hours. They can range from mild allergy symptoms to severe, life-threatening allergic reactions such as anaphylaxis. Some people only have gastrointestinal (GI) symptoms like diarrhea, nausea, and upset stomach, but skin reactions like itching and hives and asthma-like symptoms are also common. 

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What are the early signs of an alpha-gal allergy?

The symptoms of AGS typically start three to eight hours after eating mammalian meat or products, with many people reporting symptoms at night. The most common symptoms of AGS are gastrointestinal problems. Around 20% of people with AGS have only GI symptoms, which may include:

• Upset stomach

• Stomach pain

• Nausea

• Vomiting

• Diarrhea

Other alpha-gal symptoms

In addition to GI symptoms, skin reactions are also common, which may include:

• Itching

• Hives

• Scaly skin

The airways can also be involved, producing asthma-like symptoms such as:

• Shortness of breath

• Trouble breathing

• Wheezing

• Coughing

Angioedema is a more severe reaction characterized by swelling under the skin. It may include symptoms such as:

• Swelling of the lips, mouth, face, throat, or around the eyes

• Swelling could also occur on the hands or feet

• Skin welts

• Skin redness

• Rash

• Abdominal pain

The most serious AGS reaction is anaphylaxis, which generally requires emergency medical attention. Symptoms include:

• Angioedema

• Trouble breathing

• Low blood pressure

• Rapid or weak pulse

• Flushing

• Dizziness

• Fainting

• Confusion

• Loss of consciousness

• Rare symptoms of alpha-gal include joint pain and chronic hives.

Alpha-gal allergy vs. Lyme disease symptoms

In the U.S., both AGS and Lyme disease are primarily tick-borne diseases. However, while AGS is an allergy, Lyme disease is a bacterial infection. In most people, Lyme disease symptoms resolve with appropriate treatment, but AGS may typically take years to resolve as the immune system gradually loses its sensitivity to alpha-gal. Lyme disease has symptoms typical of an infection, like fever, chills, fatigue, and muscle aches. AGS often has symptoms typical of food allergies, which may include skin reactions, swelling of the face or throat, trouble breathing, and GI symptoms. 

RELATED: Lyme disease symptoms—and how to protect yourself

When to see a doctor for alpha-gal symptoms

Any food allergy symptoms should be brought to the attention of a healthcare provider. When people first start experiencing alpha-gal reactions, they may not recognize them as a food allergy. Symptoms may appear hours after eating, with many occurring at night. GI symptoms may not seem common during allergic reactions, but if these symptoms persist, tell a healthcare provider.

Any symptoms of a severe allergic reaction, such as wheezing, difficulty breathing, shortness of breath, facial swelling, racing heartbeats, or fainting, warrant immediate medical care.

An alpha-gal allergy is not easy to diagnose but generally starts with a medical history and physical examination. Many people may be referred to an allergist by their primary care physician. During a consultation, an allergist may ask about possible exposure to an allergen based on diet and other factors. The clinician may ask about outdoor activities that may have potentially led to a tick bite.

Allergists frequently use skin tests to discover sensitivities, but skin tests aren’t always reliable in diagnosing AGS. The definitive test is a blood test to detect alpha-gal immunoglobulin-E (IgE) antibodies. However, skin tests may help discover the extent of the alpha-gal allergy. If allergists can’t confirm an alpha-gal allergy, they might use a food test, which may involve eating red meat and non-red meat products on different days to see if there’s a reaction. Other tests might also be used.

Complications of AGS

Like any food allergy, people who don’t control what they eat or who don’t treat allergic reactions when they happen may experience serious and even life-threatening complications, including:

• Chronic hives

• Airway closure

• Respiratory arrest

• Low blood pressure

• Organ failure

• Irregular heart rhythm

• Death

How to treat AGS symptoms

The main treatment of AGS is to avoid tick bites or products containing alpha-gal.

In nearly all cases, people with an alpha-gal allergy will need to avoid red meat, including:

• Beef

• Pork

• Lamb

• Goat

• Venison

• Horse

• Bison

• Buffalo

• Rabbit

Other products to keep in mind that may contain alpha-gal include:

• Inner organs from mammals such as beef liver, tripe, sweetbreads, menudo, or kidneys

• Sausages wrapped in pork intestines

• Beef or pork broth, stock, or bouillon cubes

• Utensils or dishes that have been contaminated with red meat

Other meats such as chicken, turkey, fish, and shellfish do not contain alpha-gal and are safe to eat.

For most people, avoiding red meat is enough to prevent symptoms. Around 80% to 90% of people with alpha-gal syndrome do not react to dairy products. Those that do may have to avoid high-fat dairy products or all dairy products. Some people may have a wider range of alpha-gal sensitivities and may need to avoid products containing gelatins or other mammalian products.

People with AGS may also have to avoid:

• High-fat foods

• Restaurant foods cooked in fat

• Cooking fumes

• Medications, foods, or supplements containing gelatin, collagen, or carrageenan

• The cancer drug Erbitux (cetuximab), which is made with alpha-gal

• Co-factors that worsen alpha-gal allergic reactions, such as alcohol

People with AGS may need to prevent further tick bites by avoiding thick brush and wooded areas, wearing permethrin-treated clothing and insect repellants when outdoors, and checking for and removing ticks. Further exposure to tick alpha-gal can worsen the allergy. Alpha-gal antibodies may decrease in 89% of people who avoid further tick bites. 12% of people who avoid further tick bites may completely lose their alpha-gal sensitivity in five years, allowing them to add red meat to their diet.

Avoiding allergens and tick bites is the main treatment. However, medications may help treat allergic reactions. These include:

• Antihistamines to control symptoms of mild allergic reactions

• Short-acting beta agonist (SABA) inhalers such as albuterol to control asthmatic reactions

• Epinephrine injections to control more severe allergic reactions—many allergists may prescribe an epinephrine auto-injector to carry around in case of a severe reaction

• Oral cromolyn to control repeated gastrointestinal symptoms and discomfort

• Oral corticosteroids for repeated and unknown exposures

• Xolair (omalizumab) for chronic symptoms

RELATED: What you need to know about Epi-Pen alternatives

Living with AGS and signs that AGS is getting better

Some people live with AGS their entire lives. Some people improve over time. Their immune response decreases, and their symptoms get milder. Some people beat alpha-gal allergy symptoms completely after a few years. In all three cases, the way to live with the condition is to avoid exposure to red meat, avoid tick bites, and use allergy medications as directed. Once a blood test comes up negative for alpha-gal antibodies, those affected may be able to safely return to eating red meat, dairy, and anything else that’s been restricted.

RELATED: How to prevent tick bites—and, if necessary, treat them

What’s next? Additional resources for people with alpha-gal symptoms

Test and diagnostics

• Alpha-gal and red meat allergy, American Academy of Allergy Asthma & Immunology

• Current and future strategies for the diagnosis and treatment of alpha-gal syndrome (AGD), Journal of Asthma and Allergy

• Diagnosis & management of alpha-gal syndrome: lessons from 2,500 patients, Expert Reviews in Clinical Immunology

Treatments

• Diagnosis & management of alpha-gal syndrome: lessons from 2,500 patients, Expert Reviews in Clinical Immunology

Scientific studies and clinical trials

• Galactose α-1,3-galactose phenotypes, Annals of Allergy, Asthma & Immunology

• Gelatin-containing sweets can elicit anaphylaxis in a patient with sensitization to galactose-α-1,3-galactose, The Journal of Allergy and Clinical Immunology: In Practice

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