Disproportionate Reaction

Hay fever (allergic rhinitis, see Vocabulary box) is the most common immune disease in the world – an allergy which affects around ten to twenty percent of the population in industrialized countries. It is followed closely by asthma, from which more than 130 million people suffer worldwide.

These two conditions are closely related to each other. As Professor Markus Ollert of the Dermatological Clinic at the Technical University of Munich points out, "Up to 50 percent of untreated allergic rhinitis sufferers will develop asthma within five to fifteen years."

The economic consequences are correspondingly serious. In Europe alone, the major allergic conditions give rise to total costs of around 2, 29 billion.

Allergies are usually triggered by relatively harmless substances. Pollen, molds and dust may be no problem for the healthy immune system, but to the allergy sufferer they represent a threat which, in extreme cases, can even kill. When a susceptible individual comes across an allergen for the first time, he/she doesn't seem to notice anything to start with. But the rot has already set in. Experts call this the "sensitization phase". During this phase, the susceptible individual produces large quantities of antibodies to the allergen encountered. These molecules, known as "class E immunoglobulins" or "IgE", eventually become attached to mast cells, which are found primarily in the lungs, on the skin and tongue and in the mucous membranes of the nose and gastrointestinal tract.

When the susceptible individual comes into contact with the same allergen again, the antibodies formed during the first encounter instruct the mast cells to release powerful chemical substances such as histamine or heparin, resulting in the typical symptoms of allergy: runny nose, streaming eyes, sneezing and itching.

Quite clearly, the body is overreacting. By how much exactly can be determined from the levels of the aforementioned IgE antibodies produced by the immune system.

Once the allergy exists, antibodies will continue to be formed thereafter.

Go to An allergy can affect anyone
Go to A New Diagnostic Test