Allergies are regarded as diseases of modern civilisation. They occur mainly in the western industrialised nations. There, the number of allergic diseases has risen abruptly since the mid-20th century. In Europe, around 60 million people are affected by an allergy - in Germany alone the figure is probably 20 to 30 million.
Before the allergy test: How allergies work
To understand allergy testing, it's worth remembering what happens when you have an allergy: the immune system reacts with its defence mechanisms to allergens, i.e. substances that are otherwise completely harmless. As a rule, these allergens are proteins that can be found for instance in foods, pollen, animal hair and in dust mite faeces.
When an allergy occurs, the body builds up a sensitisation towards allergens. Large amounts of certain IgE antibodies that are produced attach themselves to the mast cells of the immune system. Once the allergens are reintroduced into the body, they bind to the IgE antibodies which then cause the mast cell to release the messenger histamine. Histamine causes inflammation in the body and therefore also complaints such as sneezing, runny nose, itchy eyes, skin changes, dizziness and gastrointestinal discomfort.
What kind of allergy tests are there?
There are several ways to test for allergies. A common procedure that doctors perform is the prick test. In this test, various allergens are scratched lightly under the skin. If within seconds a few wheals start to form at one of the puncture points, this indicates a sensitisation to the allergen.
Sensitisation can also be detected in the blood. Laboratories can test the concentration of specific IgE antibodies in a blood sample. The antibodies detected in such an allergy test can be assigned to allergens and in the same way to certain foods or types of animal hair.
Important: Sensitisation is not considered to represent an allergy alone. Sometimes an allergy test can reveal many IgE antibodies in the blood, but an allergic reaction will still not yet occur. Doctors speak of an allergy only where symptoms also occur. To be really sure, a provocation test can be carried out. To do this, a doctor will administer increasing doses of an allergen to your mouth or nose and monitor you for symptoms. Such a test might in itself induce an allergic shock and should therefore only take place under medical supervision!
How can I test for allergies myself?
You can carry out an allergy test in the comfort of your home, for example, using cerascreen self-tests. The tests target various types of allergies, including food allergies, pet allergies, house-dust allergy and latex allergy.
For the allergy test, take a small blood sample from your finger and send it to a specialist laboratory. The specialist laboratory then measures the concentration of specific IgE antibodies in your blood. You will then be mailed a results report that tells you whether and how much you are sensitised to the allergens tested. The results report also provides recommendations, for instance on how to reduce the burden of house dust in your bedroom or what to do if you suspect a food allergy.