In Germany, about a quarter of the population suffers from an allergy - about half of it from hay fever. Allergies have become a common disease and more and more often it affects adolescents and children. More and more people are becoming increasingly sensitive to more harmless substances, to ordinary things in everyday life and the environment, such as pollen, house dust, pet dander, the sun, food or chemicals. Why is the immune system hypersensitive to certain substances and what can anyone do to protect themselves?
What is an allergy?
Allergy is the acquired hypersensitivity (hypersensitivity) of the body to substances of the living space. The allergic reactions are basically normal immune responses, but they are misguided.
The immune system can then no longer distinguish between harmful and harmless substances and also produces too many antibodies, leading to an excessive, allergic reaction. The defense system damages the own body. Every new contact with the allergen (allergenic substance) sets this reaction in motion again.
The defense processes
To deal with unwanted and potentially dangerous intruders such as viruses or bacteria, the body has different defense strategies. One of them is to capture the invaders (= antigens) with antibodies and then make them harmless.
- Antibodies are protein bodies in the blood, which the body tunes exactly to the particular antigen. In an allergic reaction, the antigen is also called allergen. In the course of the first contact, the antibodies are first produced - otherwise nothing happens. Attackers and defenders (the immune system) have to get to know each other, so to speak.
- At the second contact, however, a violent defense wave rolls up. The antibodies not only circulate in the blood, they also migrate into the tissues. In the lymphatic system, in the nasal and oral mucosa, in the respiratory tract and in the intestine, they encounter another type of defense cells, the mast cells. These contain numerous granules, in which messenger substances such as histamine are stored. On their surface they carry binding sites for antibodies (receptors). Up to 100, 000 antibodies can be accommodated on a single mast cell. An antibody looks like a Ypsilon. He has one leg and two arms. The leg binds to a mast cell, the arms catch intruders (= antigens) and hold them tight. Once two antibodies capture one and the same intruder, so that it hangs between the two antibodies like a bridge, the mast cell releases the messenger substances stored in the granules.
- These messengers are quite aggressive. If they get from the mast cells into the surrounding tissue, they cause small inflammations there. In addition, the blood vessels expand. Depending on where this process is going on, it comes to a variety of complaints: itching, sneezing, runny nose, burning, watery eyes, skin reactions, etc.