Tick bites are to blame for the rising cases of allergies to meat from mammals and all their related products. There are some people who cannot take beef, pork, or drink milk without developing some allergic reactions such as high blood pressure or closing of the throat. Others experience skin reactions when they a wool sweater, inhale fumes.
The illness that is commonly known as “alpha-gal-allergy” is what many people are trying to cope with. It is triggered by a component in meat.
Why do allergies occur?
Allergic reactions generally occur when the immune system perceive something foreign in the body. Scientists are now trying to dig deeper to find out how alpha-gal is triggering allergies, who are in danger, and when they occur.
People who alpha-gal is affecting have been forced to change diet by switching to plant-based foods.
The allergy mystery
Dr. Sherry Van Nunen was confronted with a puzzle in 1987. She was heading the allergy department at a regional hospital in Sydney, Australia. Along with her colleagues, Van Nunen was trying to sort out mysterious occurrences of anaphylaxis. At that time, a man had been sent to contact her in an effort to find out why he kept waking up at night in the grip of some intense reaction.
Van Nunen examined the man for the common irritants but the tests turned out negative. She took a thorough look of his medical history and performed a skin test for everything the man had eaten or touched hours before he went to bed. The only potential irritant that gave positive result was meat.
Van Nunen continued receiving a few more patients. By the 1990s, she had received only six additional cases. Surprisingly, she had received more than 70 cases by 2003 that had the same problem. To understand the condition further, she lengthened the list of the questions she asked the patients. She wanted to know if the patients had a history of allergic reactions to other irritants such as fabrics, detergents, plants, or insects in their gardens.
Van Nunen recalls that people would tell her that they had been bitten by a wasp or a bee, but most of them reported lots of tick bites.
Whenever a new disease is discovered, it normally takes a long and painful period of time before it becomes the interest of scientific study. In this case, alpha-gal allergy came to the attention of researchers almost immediately it occurred in patients.
The story starts with cancer drug known as cetuximab, which dropped in the market in 2004. Out of 88 recipients in clinics in North Carolina and Tennessee, 25 were hypersensitive to the drug. Some become so sick such that they required emergency hospitalization and epinephrine injections. At about the same time, a patient collapsed and died in Bentonville, Arkansas, after receiving the first dose of cetuximab.
The news of his death reached Dr. Thomas Platts-Mills, an allergy researcher at the University of Virginia who decided to find out more about the reactions. He mobilized a team which quickly discovered the cause of the problem. The reaction to the drug occurred because people had pre-existing sensitivity, indicated by increased levels of antibodies called immunoglobulin E (IgE) to a type of sugar found in the meat of almost all mammals. The sugar, which is called galactose-alpha-1, 3-galactose or alpha-gal, is not present in humans or other primates.
After scrutinizing the patients and their families, the team found that the reactions appeared regional. Patients in North Carolina and Tennessee were allergic while those in Boston and Northern Carolina were not.
Dr. Christine Chung, a researcher from Nashville recruited a team that stumbled on a trickery clue. About one in every five patients who enrolled in her cancer clinic had high levels of IgE to alpha-gal.
The Star Tick
After further investigations by Dr. Jacob Hosen, a researcher at Platts-Mills lab, a map drawn by Centers for Disease Control and Prevention (CDC) revealed the prevalence of an infection called Rocky Mountain where cetuximab reactions had occurred. The region’s spotted fever is transmitted by tick bites.
Meat from mammals contains alpha-gal and thus is already sensitized. Consuming meat may constitute a second exposure just in the same way cetuximab infusion had been.
The star tick doesn’t receive a lot of attention in the United States, but its range is expanding globally. The expansion is mostly being fueled by climate change.
Alpha-gal reactions associated with tick bites have been reported in France, UK, Germany, Spain, Switzerland, Italy, South Korea, South Africa, and other countries.