How is the analysis for allergens in adults, skin tests and the method of immunoblotting
Many people suffer from allergic reactions. And their number is constantly growing, because the number of potential allergens only increases with time. Harmful substances enter the human body and cause an inadequate reaction. What tests do they take to identify allergies?
- Types of allergens
- When is it necessary to check for an allergy?
- Skin tests
- Benefits of a blood test
- How to prepare for a blood test?
- Conducting research
- Immunobulence method
- Features of the examination of children
Types of allergens
Any substance can become a cause of an allergy. The reaction arises from the fact that immunity does not recognize the allergen and recognizes it as alien, trying to get rid of it. The most common types of such substances are:
- Food. The reaction appears if the body gets substances or lacks some of the elements that are needed for a full-fledged digestive process. It is also associated with psychological factors. For example: as a child, they were forced to eat what they do not like, as a result, the product causes allergies. They lead to inadequate reaction of the organism nuts, seafood, citrus fruits.
- Home dust. Her immunity reacts because it contains a dust mite. The reason - the parts of his body or the products of life. It appears in autumn and winter. During this period ticks are active, and the immune system becomes weaker.
- Animals. Many believe that wool is an allergen that causes a negative reaction of the human body. This is not true. Allergens are proteins found in the cells of the skin, saliva, urine, feces and accumulating on six animals.
- Pollen of plants. Because of getting into the respiratory organs, there is pollinosis, rhinitis, asthma. Allergies cause flowers, trees, weeds, grasses.
- Inhalation allergens. Insects, their living products, seeds, latex, biomaterials, metal salts and other chemicals.
- Parasites. The organism reacts inadequately to microorganisms, because it perceives them as a danger to health. And the parasites themselves increase the risk of allergies, and the products of their vital activity. When a person suffers from helminthic invasion, the immune system weakens. This is due to the fact that it is constantly exposed to toxins released by these microorganisms. These harmful substances suppress the protective mechanism, and it reacts to those components that were previously transferred to them normally.
- Medications. In this case, the allergic reaction can easily be confused with the side effect. To allergies are products of biogenic origin, antibacterial drugs, hormonal agents.
Important!!! Rarely allergic to only one stimulus. The body does not adequately perceive several substances. Just a person does not always face all the irritants, therefore, it releases a certain allergen.
When is it necessary to check for an allergy?
Analyzes for allergens are a mandatory type of diagnosis in allergic pathologies. This will help determine what is causing the inadequate response of the body. A study is ordered by an allergist on the basis of a patient's complaints or in order to verify the reliability of the previous analysis. Usually, allergies are detected with the help of a blood test or skin tests.
The main indications for the survey are:
- Pollinosis of any type.
- Bronchial asthma.
- Atopic dermatitis.
- Allergic reaction to food or medicine.
- Glistovye infestations.
- Hereditary predisposition to allergies.
It is necessary to consult a doctor if the following symptoms occur:
- For a long time, the runny nose does not pass, the separates are watery and transparent.
- There is a pronounced inflammatory process in the mucous membranes of the nasal cavity. A person sneezes regularly and is bothered by itching.
- There is conjunctivitis, inflammation and redness of the eyelids. Sometimes scales form along the edge of the location of the eyelashes, itchiness, swelling, lacrimation, fear of light disturbs.
- There were eruptions on all body or in its separate parts. The rash is accompanied by redness, pronounced itching, unpleasant sensations.
- There is swelling of the mucous membranes of the throat, because of which it is difficult for a person to breathe.
- The patient is troubled by attacks of lack of air, bronchial spasms, Quincke's edema, cough of paroxysmal type.
If these symptoms are disturbing, then it is urgent to see a doctor and find out how to identify an allergy and eliminate it.
Conducting skin tests is that the doctor applies an allergen to the skin area and monitors the body's response to it. If there is an allergy to the applied stimulus, then the skin will have a rash, swelling and redness. If no reaction followed, then the allergen is excluded.
The sample can be carried out with the help of different methods of execution: injection, putting the stimulus into small incisions, applying a dressing containing the allergen.
In order for the analysis to yield reliable results, it is necessary to prepare. The rules for the diagnosis are as follows:
- Do not take medicines that are aimed at eliminating the allergic reaction and withdrawal of symptoms.
- Do not exercise for a couple of hours before the study.
- Do not diagnose small children, elderly people and women in an interesting situation.
- It is impossible to do or make assays during an exacerbation of disease.
The downside of these skin tests is that they can not be used to diagnose food irritants. Sometimes such a study does not show the exact result, but there is a persistent suspicion that certain substances are responsible for the negative reaction.
Then the doctor appoints provocative tests. Their essence is to apply an allergic substance to the mucous membranes of the eyes or mouth. This technique allows you to decipher more information, but it is dangerous, as it can lead to the development of complications..
Important!!! Skin tests are conducted in the presence of a qualified specialist. After all, they involve direct contact of the human skin with possible allergens..
Benefits of a blood test
Usually, doctors conduct a blood test for allergies. This method of examination has several undeniable advantages:
- There is no need for skin contact with irritants. This avoids the development of an acute allergic reaction.
- Helps to identify the allergen at any time and every person. Contraindications do not exist.
- Do not do a few tests, you need to donate blood once, and it deciphers all the stimuli.
- Due to the analysis of allergens in adults, it is possible to establish to what extent the substance is capable of causing a negative reaction of immunity.
The analysis of blood for allergens in children is much more informative and better than skin tests, so it is given preference.
How to prepare for a blood test?
A blood test requires compliance with the rules. This is necessary to obtain the exact result of the examination for the determination of allergens. The doctor is obliged before the appointment of the study to explain to the patient what preparation is necessary.
Before donating blood, follow the following recommendations:
- Hand over the blood to allergens at the time when there is no worsening of the allergy. Because in the acute course of pathology, a high level of antibodies is observed, and the result will be unreliable.
- You can not go through a study if there are viral, cold, respiratory illnesses. Also, blood tests during the exacerbation of chronic pathologies, at high temperature, intoxication of the body do not surrender.
- Stop taking medication several days before the procedure, especially antihistamines. If cancellation of therapy is not possible due to the severity of the disease, then inform the doctor.
- Three days before the analysis for allergies, stop contacting pets.
- Five days before the procedure, exclude from the diet foods that have an increased degree of allergenicity. These include citrus fruits, honey, whole milk, chocolate, nuts, seafood, berries, fruits, vegetables of red color. Do not eat foods that are made with the use of preservatives, flavor enhancers, flavors, dyes.
- The day before the study date, reduce the intensity of physical activity, especially exercise.
- Take food no later than 10 hours before blood donation. You can drink ordinary water.
- On the day of the analysis, give up coffee and smoking.
These simple rules will allow you to get the right results.
A general blood test for allergies is considered the main diagnostic technique for the patient. It is prescribed to all without restrictions, if they are disturbed by symptoms of pathology. Due to the results of the study, the doctor will determine what other methods of examination will be needed.
Blood is taken from the finger of the hand. In some cases, a biochemical blood test can be performed from the ulnar vein. If a person is sick, then they find such leukocytes for allergies like eosinophils. This is the name of special blood cells that appear in allergic, parasitic, infectious, inflammatory reactions. Erythrocyte sedimentation rate (ESR) with allergies is increased and lymphocytes are increased.
If the blood cells begin to rise, the doctor will prescribe an additional diagnosis, which determines why the level of eosinophils in the blood rises.
Medicine offers a method of research that allows you to obtain accurate and detailed information about an allergic reaction, the method of immunoblotting. Carried out using special membranes of nitrocellulose. They are striated with specific types of proteins.
If there is a certain allergen in the blood, then the band responsible for it acquires a dark color. Such a study is conducted for all people, since it has no contraindications.
During the test, panels of stimuli are used. This is the name of the standard kits on which markers of allergens are applied. The increase in allergenicity is estimated in the range of 5-100 kU / l. If it is below this value, then there is no allergic reaction.
All other decoded values indicate the presence of sensitivity of the body to certain substances. If the figure is high, this does not mean that the allergy is severe. The degree of development of pathology will be determined by the doctor, based on the results of a comprehensive diagnosis.
Features of the examination of children
In children, allergic reactions occur much more often than in adults. The study of small patients does not differ from that of adults. The only thing you can not do skin tests for a child who is under 5 years old. At this age, such a study does not provide enough information and may be unreliable.
The analysis on allergens in children is prescribed by a pediatrician or an allergist. Material is taken from the vein. The doctor conducts research from that group of irritants, which is the most possible cause of pathology. Using an enzyme immunoassay it is possible to obtain an accurate indicator of allergy in a blood test.
As soon as the doctor deciphered the blood test for allergens, he will put an accurate diagnosis and determine the treatment plan. Therapy is prescribed individually for each patient. It presupposes elimination of provoking factors, taking medications... .