Allergic reactions are an exaggerated response to the re-exposure of a substance called an allergen, as it is capable of inducing a response from the immune system of the person who suffers it.
In reality, any chemical or biological compound can generate a response after the individual is sensitized to it. However, an allergy to Alpha gal, also known as an allergy to red meat, is the first identified immune reaction that can be acquired as a consequence of an insect bite.
What is alpha gal?
Alpha gal is the diminutive or term used to refer to the carbohydrate galactose-alpha-1,3-galactose. In simpler terms a carbohydrate composed of two galactose molecules linked by an alpha bond in their portions 1 and 3 respectively.
This carbohydrate is present in the muscular tissues and body fluids of various animals, especially mammals, with the exception of primates. Also, in some drugs or compounds manufactured using the blood or serum of non-primate mammalian animals.
What is an alpha gal allergy?
Allergy to alpha gal is the exaggerated response of the immune system to the second exposure or detection of this substance in the body, which induces the release of chemical mediators and triggers an inflammatory response that can be, from itching and slight bleeding in the skin, to inflammation of the respiratory tract (channels through which air flows from the outside to the lungs and vice versa) and dilation of blood vessels.
Inflammation of the airways can cause suffocation, dilation of blood vessels can cause heart attacks, both situations are life threatening.
Causes of alpha gal allergy.
The cause of the allergy is the presence of the specific Immunoglobulin E antibody for this Alpha gal molecule in the individual’s blood. The way this antibody is secreted is unique in immunology to date.
- Innate. There are people who are born with this rare allergy to red meat and whose allergic response will depend on the amount of alpha gal present in ingested meat, animal gelatin, or animal product.
- The bite of a tick called Amblyomma americanum, it can induce a reconfiguration of the immune system of the infected individual, causing the generation of the IgE antibody specific for alpha gal. Making the individual allergic to alpha gal after the bite. This is the first time that an allergy can be transmitted or contagious has been recorded.
What are the symptoms of an alpha gal allergy?
The symptoms and the severity of these depend on the amount of alpha gal present in the body and the response that it can trigger. The wide variety of allergic responses ranges from mild to death from anaphylaxis (allergic reaction).
The response time of the allergic reaction usually occurs after 3 to 6 hours after ingesting the animal product, usually red meat, or having been exposed to a product that contains alpha gal.
- Intense itching. Exaggerated itching of the palms of the hands and the soles of the feet after the ingestion of a product of animal origin.
- Difficulty breathing. Due to the allergic reaction this can be severe and inflame the airways causing their obstruction. (can be fatal).
- Dizziness and weakness. Patients may experience dizziness and weakness due to the low oxygen reaching the brain.
- Inflammation of the skin and mucous membranes. The reaction causes the outermost layer of the skin to receive the complexes formed of antigen and antibody, producing inflammation that can be seen as red areas of various sizes. The lips tend to increase in volume.
- Hypotension. Products released by the body to fight the antibody cause blood vessels to dilate, lowering blood pressure to critical levels, which can be fatal.
- Angioedema. It is the inflammation of the walls of the blood vessels.
- Skin rashes. The inflammation of the walls of the blood vessels can cause from small red blood spots that disappear under pressure, the size of the head of a pin, to spots with diameters greater than 3 or 5 cm.
- Anaphylactic shock. It is the most dramatic and exaggerated response in which all the symptoms and signs of the allergic reaction are presented simultaneously and in the most intense way that can occur. Without immediate medical help, this reaction is potentially fatal within just a couple of minutes.
It should be remembered that an allergy to alpha gal occurs three to six hours after eating red meat. Birds do not cause it.