Meat Allergy Symptoms, Treatment, and Foods to Avoid

It’s unclear how many people have a pork allergy or red meat allergy, but the condition can occur in both children and adults. Some studies report up to 10% of people living in certain U.S. regions show evidence of possible alpha-gal allergy (IgE antibodies), a common cause of allergic reaction to meats. Others identify up to 3% of the population as having an alpha-gal allergy but warn there may be more misdiagnosed or undiagnosed cases. The proteins in meat that can trigger an allergy are known as allergens.

What Are the Symptoms of a Meat Allergy?

With a true meat allergy, the body’s immune system will overreact whenever you consume the type of meat that you’re allergic to. The response can be rapid (as with a pork allergy) or it can take a few hours for symptoms to emerge, as is the case with beef and alpha-gal allergies.

An allergic reaction happens when the body releases a chemical known as histamine into the bloodstream. Histamine can trigger immediate and sometimes profound effects, causing blood vessels to dilate and mucus-producing cells to activate.

This can lead to a cascade of symptoms affecting the skin, digestive tract, and respiratory tract. The most common symptoms, as reported in a study of 261 people with meat-related allergies, include:

• Hives (urticaria) in 93%
• Gastrointestinal symptoms (stomach pain, diarrhea, nausea, vomiting) in 64%

Other symptoms associated with beef and pork allergy include:

• Generalized tissue swelling (angioedema)
• Headaches
• Rash
• Sneezing and/or a runny or stuffy nose
• Swollen, teary eyes
• Rapid heart rate

Anaphylaxis occurred in 60% of the cases in the study, with symptoms of low blood pressure, lightheadedness, and shortness of breath. With a red meat allergy, anaphylaxis can occur immediately or up to several hours after the meat has been consumed.

 What Causes a Meat Allergy?

A meat allergy can develop at any stage in life, and certain people are at greater risk, including those with specific blood types, past infections, tick bites, eczema, or other food allergies. There is no known cure for a meat allergy, though sometimes the symptoms may recede over time.

As with all allergies, the underlying cause of a meat allergy is unknown. With that being said, scientists have gained greater insights into the key factors that trigger red meat allergies and poultry allergies.

Pork Allergy

Pork can fall under the red meat allergy category, due to the same alpha-gal exposure. But it’s also possible that people have only a pork allergy because they have a cross-reactive response to pork, rather than a true allergy to the meat.

With cross-reactivity, the body reacts to something that resembles a substance you are allergic to. In the case of pork, it’s usually cat allergens. Known as pork-cat syndrome, the reaction is triggered by the similar molecular structure of cat and pork albumin (a type of protein).

While people allergic to pork are typically allergic to cats, the opposite is not true. As such, the cat allergy is considered the true allergy, while the pork allergy is the cross-reactive response.

Red Meat Allergy

With regards to beef, lamb, and similar meats, the allergen is a specific sugar molecule—alpha-gal sugar—which is found in almost every mammal except humans.

Note that this molecule is not the same as the sugar that is commonly found in cookies, cakes, and other sweet foods, and you do not need to read labels to specifically avoid sugar if you are allergic to alpha-gal.

How Blood Type Affects Red Meat Allergies

Red meat allergy, also called mammalian meat allergy (MMA) or alpha-gal allergy, occurs most frequently in people with an A or O blood type. According to researchers, this is because the B antigen in AB or B blood types most resembles the allergen that triggers a meat allergy.

While an A or O blood type may increase a person’s risk of a true meat allergy, research suggests that certain infections or co-existing allergies may trigger a symptomatic response or amplify its effects.

A Tick Bite Can Trigger the Allergy

One of the most common triggers is the bite of a lone star tick (named for the single white marking on its back). It is found primarily in the Southern and Central United States, though its range is expanding and includes midwestern states where the wild turkey is common, as well as heavily wooded areas in eastern states where white-tailed deer thrive.

The lone star tick—also known as a turkey tick or northeastern water tick—sucks blood from mammals whose meat contains alpha-gal sugar. When the tick feeds on a human, it introduces those sugars into the bloodstream, potentially making the person sensitive to alpha-gal.

While beef is most commonly associated with this effect, any other meat protein can also trigger a response.

Poultry Allergy

Allergic reactions to poultry are even less common than those involving red meat.

Egg Allergy

Some people with a known egg allergy will also have a cross-reactive condition known as bird-egg syndrome, in which exposure to down feathers can cause respiratory symptoms. Interestingly enough, the condition is associated with an allergy to chicken eggs but not the chicken itself.

Poultry Meat Allergy

A true poultry allergy is most commonly seen in adolescents and young adults, although the first signs may occur in the preschool years. People with a poultry allergy are often allergic to fish and possibly shrimp as well. For these individuals, a co-existing egg allergy is rare and the risk of anaphylaxis is low.

Meat Allergy Foods to Avoid

It’s clear that a pork allergy means it’s best to avoid ribs or chops, but it’s not quite as clear that products like gelatin contain pork-based ingredients. People who can’t eat beef may not be aware that meat from sheep can cause symptoms, and chicken allergies may really be due to a cross-reaction caused by fish allergy.

Researchers have found a number of links between meat allergies and other foods too, especially with a primary beef allergy (not caused by alpha-gal). Beef allergy in children who have a cow’s milk allergy may be found in up to 20% of cases. Other foods to avoid include:

• Lamb, rabbit, venison (deer meat)
• Gelatins made from beef
• Beef broth, bouillon, or products made with them

People with pork allergies should avoid a number of foods made with pork product, including:

• Marshmallows
• Chili sauces and bag seasoning mixes
• Refrigerated pastry products (pie shells and biscuits)
• Some processed snacks, including potato chips, Kellogg fruit snacks, and Hostess cupcakes

With a poultry allergy, try to avoid products with poultry ingredients. These include:

• Eggs, as well as chicken or turkey meat
• Seasonings and curry dishes
• Canned soups

The allergic responses aren’t always the same, but generally, there are foods to avoid with a specific meat allergy. Talk to your healthcare provider about your dietary concerns.

How Is a Meat Allergy Diagnosed?

You might wonder if you have a meat allergy if you experience symptoms when you eat certain types of meat.

To get a diagnosis, you would need to see a specialist known as an allergist who can perform a series of common allergy tests.

These include:

• An allergy blood test able to detect IgE antibodies specific to the different types of meat, poultry, and alpha gal
• A skin prick test in which small amounts of meat protein are placed beneath the skin to see if they trigger a skin reaction
• An elimination diet to remove suspected meat allergens from your diet to see if the symptoms improve

Results of a skin prick test can be completed and provide results in about 15 minutes. Other diagnostic methods take longer: Blood test results that look for certain antibodies are usually available in about a week. A trial of an elimination diet could take weeks or months.

Less commonly, an oral challenge may be used. This involves eating meat to see if it triggers a reaction. This should only be performed under the direction of a board-certified allergist in order to get immediate care if you develop an adverse reaction.

How Is a Meat Allergy Treated?

Prevention is the best option for a meat allergy by avoiding the specific meat or meat by-products that you’re allergic to. This includes checking all food labels (particularly sausages, pâtés, and other mixed-meat products) and restaurant ingredients whenever dining out.

If that type of meat is a major staple of your diet, consider meeting with a dietitian or healthcare provider who can help you find alternative sources of protein while ensuring that you meet your daily nutritional needs.

What to Do For Accidental Exposure

If you accidentally eat a problematic meat and have an uncomplicated reaction, an over-the-counter antihistamine will often help relieve rash. Those with asthma will typically need a rescue inhaler to ease respiratory distress.

If you have experienced a severe reaction in the past or are at risk of anaphylaxis, you need to carry an EpiPen to inject yourself with epinephrine (adrenaline) in an emergency.

If epinephrine is given at home, emergency care is usually recommended immediately afterward in case additional treatment is required.

Summary

A meat allergy is an uncommon type of food allergy, mainly because the allergens in meat tend to be neutralized during cooking. Even so, meat allergies do occur and can cause symptoms.

A red meat allergy is the most common “true” meat allergy, mainly affecting people with A or O blood types. Pork allergy is often due to a cross-reactive allergy to cats. A poultry allergy is not the same as an egg allergy—and many people who have one of these do not also have the other.

The avoidance of trigger foods is the best way to deal with any food allergy, and a meat allergy is no exception. In the event of accidental exposure, oral antihistamines, a rescue inhaler, or an epinephrine auto-injector (EpiPen) may be needed. Speak with your healthcare provider if allergy symptoms persist despite the exclusion of a presumed food allergen.