In detecting an allergen, the medical history is always the most important
The doctor will first of all conduct a family interview. He will ask the sick person (and in the case of a child - his parents):
- about the frequency of food allergy symptoms and their severity
- to associate specific ailments with the intake of certain foods
- for medicines
In addition, the patient will be thoroughly examined. Additional research is often undertaken; some of them will now be discussed.
Preliminary findings of the medical history should confirm diagnostic tests
Allergy and food intolerance can be properly recognized using scientifically validated tests. If someone suspects that they have a food allergy, they should go to the doctor to make sure that the symptoms are not associated with a completely different mechanism. The family doctor will take appropriate diagnostic and therapeutic measures himself or, if necessary, may refer the patient to a specialist - allergologist.
Skin tests
On the basis of the medical food interview, the purified solutions of food products used for the test are selected. Intradermal injections (or rub the skin) are performed using these solutions and then the local reaction is observed. The diagnostic value of skin tests is in many cases controversial. Therefore, a positive skin test result does not mean that you are allergic to the substance.
Elimination diets
The elimination diet is the basic diagnostic test for the detection of a food allergen. The principle of using elimination diets is to remove from the menu a suspect about causing an allergy to a food product or group of products for a period of about 2 weeks. If the symptoms disappear at this time, it may indicate allergy (or intolerance) - caused by this product. Then it gradually returns to the product, starting with very small amounts, which are then gradually increased until the usual consumption. The next suspicious groups of food products are followed in a similar manner. After completing the test, you can specify food products that should be avoided.
RAST tests
These tests allow the determination of allergens in laboratory conditions. They consist in mixing small amounts of blood of a patient with a food product extract in a test tube. If there is a real allergy, the blood produces antibodies that fight the allergenic protein. The test detects the presence of antibodies produced by the immune system.
Exposition tests
The principle of conducting these tests is to provide the patient with a suspicious allergen (eg milk, fish, soy) in the form of a capsule under strict medical supervision. The doctor observes the body's response to individual suspect substances. The occurrence of disease symptoms speaks for the diagnosis of allergy to a specific allergen.
In practice, you can also meet with several other tests used in the diagnosis of food allergy. You should be aware that some of these tests have no proven value and their performance can only be a waste of time and money.
He prepared:
dr n. med Janusz Ciok
Institute of Food and Nutrition
