Red meat allergy, also known as Alpha-gal syndrome, is derived from the carbohydrate. That causes the disease, galactose-alpha-1, 3-galactose (or alpha-gal for short). It is believed that specific antibodies to this carbohydrate are what trigger an immune response when red meat is eaten. Alpha-gal is found in various parts of mammals. Including red meat, kidneys, milk, gelatin, and blood.

Causes of meat allergy

1. Alpha-gal syndrome
   is believed to be initiated by a bite from a deer tick in the Amblyomma group, including the lone star tick found in the United States. Or the Ixodes tick found in Australia, Europe, South Africa, and Japan (Figure 1). The saliva of these ticks contains alpha-gal. When this substance enters the body, it stimulates the immune system and creates allergic antibodies. Eating mammalian meat that contains alpha-gal, such as beef, pork, deer, or rabbit, causes an allergic reaction. There is limited data on deer ticks in Thailand. There have been reports of the Ixodes tick being associated with Lyme disease in the past.
2. Pork-cat syndrome is caused by contact with cats and previous cat allergies. The allergy is to the cat serum albumin allergen Fel d 2 (cat serum albumin). This substance can cross-allergic to the albumin protein in pork Sus s 1 (pork serum albumin). It can also cross-allergic to beef Bos d 6 (bovine serum albumin), as shown in Figure 3.
3. Primary beef allergy is most commonly found in children and is caused by an allergy to the beef protein bovine serum albumin (Bos d 6). In this group, more than 90% are also allergic to cow’s milk. Most are able to consume it as they get older.

Signs and symptoms

Symptoms of allergic reactions usually appear 2 to 6 hours after consuming red meat. It is believed that the slower allergic reaction occurs because the trigger is a carbohydrate, which takes longer to activate the immune system. ทางเข้า UFABET สำหรับสมาชิกใหม่ สมัครวันนี้ รับโบนัสฟรี Allergic reactions can range from mild to severe and include:

• Hives, itching
• Stomach ache, nausea, vomiting
• Cough, shortness of breath, bronchial stenosis
• Swollen mouth, swollen tongue, swollen eyelids
• Low blood pressure, rapid heart rate
• Fainted and lost consciousness

Diagnosis

Skin tests usually involve a subcutaneous prick or a meat extracts intradermal test (Figure 4), which is positive for pork, lamb and beef and negative for chicken and turkey. However, this test method has limitations, with inconsistent results from different studies and potentially unsafe.

Blood test for specific IgE antibodies to alpha-gal (galactose-alpha-1,3-galactose).

Blood tests for the molecular makeup of allergens include Fel d 2 (cat serum albumin), Sus s 1 (pork serum albumin), and Bos d 6 (bovine serum albumin).

Oral food challenge remains the most definitive diagnosis.

Figure 4. Intradermal skin test for different meat extracts. 

Allergy recovery rate, red meat steak chance again?

There is limited follow-up data on this group of patients at present. Some studies have found that alpha-gal antibodies decline over time. Approximately 1% to 10% of patients are able to overcome their allergy and resume eating red meat.