- Allergic tests - indications for allergy tests
- Allergy tests - why are they important?
- Allergic tests - medical interview
- Allergic tests - skin tests
- Allergic tests - blood tests
- Allergic tests - provocation tests
- Allergic tests - elimination tests
Allergy tests are recommended in the case of suspected skin, inhalation or contact allergy. The result of an allergy test helps your doctor to recognize or rule out an allergy. When do allergy tests need to be performed, what are they and what tests can an allergy sufferer undergo? How are allergy tests going?
Allergy testsis an important element of the procedure that allows to confirm or exclude an allergy, the correct diagnosis of which is one of the most difficult challenges in medical diagnostics.Allergic testsmake it easier for doctors to assess the type of disease in a patient.
It is worth remembering, however, that the results obtained after their execution are not unambiguous. Unfortunately,each of the diagnostic methods used in allergy assessment has its drawbacks and limitations . There are no allergy tests of excellent sensitivity and specificity. A negative result of each of them does not exclude the presence of an allergen. The results of the tests ordered by the doctor are only a hint in the diagnostic process for him.
The basis of the diagnostic process is a correctly conducted medical interview. During the visit, the specialist asks the patient about their symptoms, reactions to contact with potential allergens and the history of diseases. Unfortunately, in many cases, this information is insufficient to unravel the mystery of the type of disease. In such cases, allergy tests are an auxiliary tool that helps the doctor to make a proper diagnosis.
The proper analysis of the patient's results and symptoms is an extremely difficult task. Sometimes the information from basic allergy tests does not match your medical history. These situations are an indication for further, more detailed research.
Allergic tests - indications for allergy tests
Symptoms that may be an indication for allergy tests:
- nasal mucosa swelling;
- rhinitis;
- runny nose;
- fits of sneezing;
- red, itchy or burning eyes;
- watery eyes;
- bronchospasm;
- difficulty breathing;
- cough;
- impaired hearing resulting from obstruction of the proboscisEustachian;
- rash, eczema or hives;
- puffiness;
- itchy skin;
- headaches;
- a feeling of heaviness.
Patients also often develop mental symptoms, collectively referred to as "allergic irritability syndrome". These include:
- fatigue,
- weariness,
- fits of anger,
- deterioration of concentration,
- irritation.
Allergy tests - why are they important?
Allergy tests help to recognize the type of disease, and therefore allow you to undertake the appropriate type of treatment. The use of appropriate therapy can significantly improve the mental and social life of the patient. An improperly diagnosed and untreated allergy can lead to problems that are severe throughout the patient's life. The symptoms of this disease often result in decreased activity at work or school.
Patients withdraw from family life and meetings with friends due to their malaise.
Antihistamines used in allergic rhinitis also have a negative effect on the mental state of the patient. They depress the nervous system, causing a feeling of drowsiness. The use of allergy tests for the proper diagnosis of the disease allows for the appropriate treatment and limitation of contact with the allergen. As a result, the patient can limit the frequency of taking antihistamines.
Allergic tests - medical interview
Before performing allergy tests, it is advisable to talk to a specialist, known as a medical interview. During it, the correlation between the situations of exposure to various types of potential allergens and the symptoms occurring in the patient is determined. Finding this relationship is easy in the case of an immediate reaction to contact with the substance.
However, it happens that allergic symptoms appear hours or even days after exposure to the allergen. In such situations, proper diagnosis is very difficult. In these situations, it is imperative to perform specific allergy tests. A helpful tool during a medical interview is the pollen calendar.
It facilitates the diagnosis of pollen allergy based on the periods of the year during which symptoms are manifested. Based on this information, a specialist doctor can refer the patient to allergy tests for specific plant allergens.
Allergic tests - skin tests
The basic tests used in the diagnosis of allergies areskin tests . Usually, they are the first step towards the right one, after a medical interviewdiagnosis of the disease. Their advantages are low costs and a simple execution procedure. During this type of research, the patient's skin is exposed to point contact with the allergen. The test result is determined by the local allergic reaction.
There are the following types of skin tests in the diagnosis of allergies:
- Intradermal tests- are based on the intradermal injection of a small amount of the allergen.
- Spot tests- in this procedure, a drop of a solution containing the allergen is placed on the patient's skin. Then the place is punctured with a needle. This test is safer than the intradermal test, but it is less sensitive.
- Patch tests- they consist of putting paper discs soaked in a solution containing the allergen on the skin.
In all types of skin tests, the results are determined by the diameter of the blister formed at the site of contact with the allergen, after 15-20 minutes, but this type of test is only a guide in the diagnostic process. Negative results do not exclude the existence of an allergy in the patient. Positive, however, appear in even 15-30% of patients in whom this disease is not present.
What to watch out for in connection with skin testing:
- These types of allergy tests require discontinuation of antihistamines, i.e. symptomatic antiallergic drugs. Usually for two weeks, although this period, depending on the preparation, may be longer.
- Skin testing should not be done during pregnancy. Contact with an allergen during this procedure may cause a violent reaction in the body, harmful to the baby.
- Contraindication to skin patch tests is the use of drugs from the group of glucocorticosteroids.
Skin testing is not recommended for some patients. This applies to:
- patients for whom it may be dangerous to withdraw histamine medications,
- patients at risk of a severe anaphylactic reaction as a result of contact with the antigen during the test.
- patients with severe and extensive skin lesions.
Allergic tests - blood tests
For patients for whom skin testing is inappropriate, doctors usually order allergy blood tests. This type of test is performed in a laboratory using a blood sample. During the procedure, the patient has no direct contact with the allergen.
Therefore, the risk of an anaphylactic reaction during the test is eliminated. Another advantage of diagnostic allergy blood tests is that there is no need for itwithdrawal of antihistamines. Blood allergy tests are also ordered in situations where the results of skin tests are inconsistent with the medical history.
Blood tests can be performed independently of:
- age of the patient,
- skin condition,
- disease symptoms severity,
- medication taken,
- pregnant.
During this type of research, it determines the concentration of specific IgE antibodies in the blood. The obtained results help the physician to diagnose how various substances may affect the intensity of the patient's symptoms.
Laboratory methods for measuring specific IgE antibodies are:
- ELISA and EIA enzyme immunoassays,
- RAST radioallergenic tests,
- FEIA fluorescent enzyme immunoassays.
Correctly interpreting blood test results is no easy task. 15-20% of patients have specific IgE antibodies, with no allergic symptoms. Such people are not sick, but are at an increased risk of developing an allergy.
Allergic tests - provocation tests
A provocation test introduces a small amount of the allergen into the body. The substance is usually administered orally or by inhalation. Methods of this type are used relatively rarely. They are sometimes used in the diagnosis of food or drug allergies. The course of the examination must be strictly controlled by an allergist.
Allergic tests - elimination tests
The elimination test method is most often used in the case of suspected food or drug allergies. During the study, the patient is advised to modify the diet so that he completely avoids a specific allergen for a certain period of time. If he experiences significant improvement, it is often recommended to re-enter the menu to see if symptoms return.
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