In order to find out whether you suffer from an allergy, and if so, what kind, the doctor will carry out an allergy test with you. Different methods are used for this. In this article, you will learn about the most common test methods.
Allergy test: Possible test procedures
Before the actual test procedure is carried out in practice, you will have to fill out a questionnaire and have a doctor’s consultation in every doctor’s practice. This anamnesis is used to find out which method or test procedure must be used.
- The most commonly performed tests are the prick test, patch test and provocation test as possible methods to test for an allergy.
- All three test procedures are associated with no or very little pain for the patient.
- Skin redness, swelling, itching or difficulty breathing may occur during the tests.
- They are sometimes intentional, so they can tell the doctor if there is an allergy and how severe it is.
- A comprehensive blood test is part of every professional allergy test. Certain allergens can be detected on the basis of the blood count.
1. prick test – the best-known method
The prick test is also called the intracutaneous test or the rub or scratch test. Intracutaneous means that something is put into the skin.
- The test is usually done on the forearms (sitting) or on the back (prone).
- The patient is given certain allergens as a drop of concentrate liquid applied to the skin. Usually with a pipette.
- The applicator notes a code next to each drop so that an assignment to the allergen can take place afterwards.
- Then each drop is pricked or scratched. Rubbing is also possible. This introduces the allergen into or under the skin.
- The patient must now sit or lie still for 20 to 30 minutes until the reactions have occurred.
- The skin areas are then wiped and the result is read and noted. The doctor then evaluates the result report.
- The more the affected and pricked skin area is reddened and has formed a wheal, the stronger the allergic reaction is in the patient for the respective allergen.
- A redness or wheal will always occur, by the way. This is the checkpoint for the applicator that the allergy test is working.
2. patch test – skin test
The technical word for this test is epicutaneous test. Epicutaneous stands for “on the skin”. It is used for patients who are allergic to soap, jewellery or any cosmetics.
- This test takes place on the surface of the patient’s skin.
- The substance to be tested is applied to an area of skin (usually the arm) using a patch.
- Because the patch usually remains on the skin for a long time, it is not allowed to shower or bathe during the test procedure.
- Two to three days later, the doctor removes the patch and assesses the result.
- An allergic reaction to the substance contained in the patch and thus tested is present if itching has occurred, the skin site shows redness or swelling.
- A very strong allergic reaction can be recognised if blisters have also formed.
3. provocation test – only under medical supervision
In the provocation test, as the word implies, the patient is provoked. This means that the patient is administered the suspected allergenic substance and waits to see what effect it produces. The patient remains under close observation during the entire testing procedure and to be able to act immediately in case of emergency.
- Hay fever: Here, eye or nose drops are administered with the allergen contained.
- Asthma: The asthmatic sits in a cabin for a lung function test. Every now and then he gets test substances blown into his mouthpiece via a tube, which have to be inhaled.
- Food and medicine: The patient takes the test substance (food or medicine) in the morning on an empty stomach.
- The provocation test procedures are not pleasant for the patient. Since you already know what is coming, your psyche often plays tricks on you and you overreact. Medical supervision is mandatory for the test.
