HaberTürk – July 17,2021
If you are allergic to red meat, don’t let your feast of sacrifice be poisoned. Pay attention to the symptoms of red meat allergy on Eid-al-Adha. Allergy symptoms may occur immediately after consumption of meat or may be as late as three to six hours. Founder of Istanbul Allergy and President of Allergy and Asthma Association Prof. Dr. Ahmet Akçay gave detailed information about red meat allergy.
Meat allergy is defined as the appearance of fatal reactions such as a drop in blood pressure and fainting, as well as symptoms such as itching, hives, lip swelling, vomiting, abdominal pain and diarrhea, to allergens in the body after consumption of meat.
FREQUENCY OF MEAT ALLERGIES
Although the exact frequency of meat allergies is not known, allergies were reported in 3 to 15 percent of children and 3 percent of adults among patients with food allergies. The low prevalence of this allergy may be partly attributable to the fact that most meats are eaten in cooked form and that cooking often lowers the immunogenicity of allergens. Beef allergy prevalence is the most frequently reported meat allergy. However, a beef allergy may be as high as 20 percent in children who are allergic to cow’s milk.
RISK FACTORS
Risk factors for the development of allergy to meat are not fully defined and may differ depending on the allergen to which the patient is sensitive:
● Increasing evidence suggests that multiple tick bites may be a risk factor for allergy to red meats.
●A relationship has been noted between A and O blood groups and susceptibility to galactose-alpha-1,3-galactose (alpha-gal).
●Children with atopic dermatitis or cow’s milk allergy may be at increased risk.
●Patients with gelatin allergy may also be sensitive to meats or be clinically reactive.
ALLERGENS CAUSED BY MEAT ALLERGIES
Both protein and carbohydrate allergens have been identified as responsible for IgE-mediated meat allergic reactions. Serum albumins and immunoglobulins appear to be primary allergenic proteins in beef and other mammalian meats. Since these allergens are also found in milk, red meat allergy is often seen in children with milk allergy.
The other allergen is the alpha-gal allergen and is actually the blood group substance of mammals other than humans and monkeys. This is a substance in the structure of carbohydrates and is found in meats, kidneys, gelatin. This allergen combines with lipids and proteins and becomes an allergen.
HOW DOES RED MEAT ALLERGY DEVELOP?
Due to milk allergy
Children with milk allergy may develop an allergy to beef at a rate of 20% due to cross-reaction, as the allergenic proteins in milk are also present in beef. With good cooking, allergy symptoms may not be seen.
Linked to cat allergy
Those with cat allergies may be allergic to pork due to cross-reaction. Those with pork allergy may be allergic to beef and pork due to cross-reactivity. Be careful if you are allergic to cat hair.
Tick bite
Ticks bite animals such as cows and sheep and suck their blood. Alpha gal, a mammalian blood group allergen, is found in the stomach of ticks. When ticks bite humans, these allergens infect people’s blood and cause antibodies to develop. As a result of this, allergy symptoms occur 3 to 6 hours after the consumption of red meat.
WHAT ARE THE SYMPTOMS OF RED MEAT ALLERGY?
Both immunoglobulin E (IgE)-mediated and non-IgE-mediated forms of meat allergy have been described. According to these forms, the symptoms also differ.
Red meat allergy due to IgE usually develops due to milk allergy and the symptoms of red meat allergy, which develops due to cat allergy, manifest themselves within 2 hours after meat intake. Symptoms such as hives on the skin, swelling of the lips and tingling in the mouth occur especially after eating meat. Symptoms such as abdominal pain, vomiting and diarrhea may also be seen. Sometimes, it can cause allergic rhinitis and asthma symptoms, as well as allergic shock, which is a fatal reaction in the form of a drop in blood pressure and fainting.
Those who are sensitized due to tick bites usually show symptoms 3-6 hours after ingestion of meat. Because after a tick bite, you become sensitive to the alpha gal allergen. In order for beef containing alpha gal to develop allergy, this allergen gains the potential to cause allergy by binding to lipid or protein. Therefore, the reaction is delayed.
Red meat allergy that is not related to IgE may show symptoms as an allergic disease of the esophagus called eosinophilic esophagitis and red meat protein enterocolitis, which manifests itself as reflux, difficulty in swallowing and chest pain that does not respond to treatment. In enterocolitis syndrome, recurrent vomiting and diarrhea symptoms are observed 3-4 hours after red meat intake.
Patients with a beef allergy may react to mutton or pork, but rarely to poultry or fish.
HOW IS DIAGNOSED?
First of all, clinical symptoms should be compatible with red meat allergy. Exercise, alcohol and pain medication use, which may trigger red meat allergy, should be questioned. It is very important that those with red meat allergy are evaluated by allergy specialists. With skin testing, allergy testing is done with red meat allergens and sometimes with fresh meat. With the molecular allergy test, the components that cause red meat allergy can be revealed in detail. Antibody to alpha-gal allergen is evaluated.
For those with suspicious red meat allergy test results, a definitive diagnosis is made by performing a challenge test. The results are evaluated together with the clinical symptoms and the diagnosis is made.
TREATMENT
Management of food allergy most commonly involves avoiding red meat. If the patient has a reaction to raw or undercooked meat, determining whether the meat is well-done tolerated may be helpful, as the patient can retain the food in the cooked form in their diet.
Patients with an immunoglobulin E (IgE)-mediated meat allergy should be equipped with an epinephrine autoinjector and taught how and when to use it. General issues of food-borne anaphylaxis and avoidance of food allergens have been reviewed elsewhere.
Few reports of successful desensitization protocols have been published in both adults and children with alpha-gal allergy. As alpha-gal allergy appears to improve over time without additional tick bites, it is unclear whether the risks associated with immunological desensitization confer benefit beyond the natural history of the syndrome.
CAN RED MEAT ALLERGY CORRECT?
Children with cow’s milk allergy who are allergic to beef (representing the largest group of children with meat allergies) tend to outgrow both beef and cow’s milk sensitivities. In one study, beef tolerance was achieved after a median of three years and was reported to precede cow’s milk tolerance in those with allergies to both foods.
Published data on the natural history of meat allergy in adults are scarce. Case reports show that some people who acquire the allergy as adults lose sensitivity over time.
The natural history of reactions caused by sensitization to galactose-alpha-1,3-galactose (alpha-gal) is not well studied. While no data from long-term series or controlled studies are available, preliminary evidence from the author’s study suggests that IgE antibodies to alpha-gal decrease over time in some patients. However, additional tick bites appear to increase antibody levels.
