Glossary Allergy

Allergy

Allergy test (Photo: GSF)

Whether it’s asthma, hay fever, an insect venom allergy or a food allergy – the clinical pictures have one thing in common. In each case they are an incorrect response of the body’s immune system. The immune system comes into contact with harmless substances and mounts a vigorous defense against them because it perceives the substances to be harmful pathogens. It tries to rid the body of the perceived invader by entirely inappropriate, exaggerated means, which can lead to severe inflammation.

What is the cause of an allergy, what is to blame? The environment? Genes? Or a combination of the two? The last choice is the correct answer.Today we know that neither genetic nor environmental factors by themselves are responsible for allergies, but rather that they result from the interaction of various factors.

If you are allergic, there’s a good chance that you are continuing a family tradition. A child with one allergic parent has a 30-50 percent risk of developing an allergy as well. If both parents are allergic, the chances of the child developing an allergy increase to 66-80 percent. Studies on twins have shown, however, that monozygotic twins develop the same kind of allergy only in between 25 and 50 percent of the cases. Often one twin has an allergy and the other not. This shows that the genetic predisposition for an allergy is anchored in the DNA, but that the triggers are certain environmental factors. The immune system must constantly decide whether foreign substances are harmless or whether they are harmful invaders. Small differences in the environment are sufficient to steer the daily decisions of one twin’s immune system in the direction of an allergy, while the other twin does not develop any disease.

In Germany, allergies affect one in four people. Moreover, due to increasing environmental pollution/stress, the tendency is rising.