- By tick bites, sugar molecules can get from the animal into the human body.
- In some cases, the immune system reacts radically the next time it deals with this molecule, which is also found in red meat.
- Whether well-done, medium or bloody makes no difference. Safe for those affected are poultry and fish.
In the evening between eight and nine o'clock the passionate hunter had consumed his steaks in a convivial round, in the middle of the night he awoke with itching all over his body. The 58-year-old felt as if he had fallen into a pile of nettles. He could not explain the allergic reaction, but as a result, it happened again and again that the man could not sleep at night, because he hives the hives. Sometimes dizziness was added, blood pressure dropped or respiratory distress set in.
When the patient came to Tilo Biedermann's clinic to find out what he was allergic to, the dermatologist had a suspicion. After all, the man was always in the forest and corridor on the road and had to endure several tick bites over the years. "The patient has developed an allergy to red meat," says the head of the Department of Dermatology at the Technical University of Munich. "In rare cases, this is triggered by repeated contact with ticks."
During the long sucking process in the skin ticks absorb blood, mix it with the contents of their digestive tract and spit it out again. In this way, a sugar side chain called alpha-galactose gets from the animal to the human body. At some point in the course of evolution, people have lost the ability to make the substance themselves. If they come into contact with it – for example through tick bites – the body recognizes the substance as foreign and can react allergic to repeated contact if it is presented as an ingredient of red meat. "This is a kind of allergy vaccination on the skin," says Biedermann, whose working group in Munich Germany has the most experience with the rare affliction. "Endangered are especially people who have many tick bites, because they are often out with dogs or working as a forester or hunter."
Now the tick season starts again, and Biedermann's team has just published a review article with the latest findings. Thus, the allergic skin reaction blooms particularly strong at the injection site of the tick. For consumption, poultry and fish are harmless, but offal such as pork kidney or sour lungs have high allergy potential. "Whether well-done, medium or bloody makes no difference," says Biedermann.
There is no treatment for meat allergy, but provocative tests under medical supervision show that some sufferers can eat two, three slices of roast before symptoms start. "A few bacon cubes in a salad or a sausage bread then do nothing," calmed Biedermann. However, there are other dangers that may sometimes arise: The allergenic substance can also enter the body via medications that require animal cells. The allergy of the 58-year-old turned out to be particularly treacherous. Because they contain gelatin from animal protein, the patient responded to his favorite gummy bears. However, the dose was considerable; he had consumed 250 grams in an hour.