Currently, the prevalence of allergic diseases is quite wide. Itching, skin rash, swelling of the mucous membranes are familiar to almost every person, and about 30% of the population regularly suffers from allergies.
There are times when the allergen is obvious and the entire treatment is reduced only to its elimination. However, the opposite situation also takes place - signs of an allergic reaction are evident, and the cause is unknown. Constantly saved with antihistamines, drops or injections is a dubious way out. Therefore, the real salvation for such people is the presence in the medical diagnosis of some laboratory tests that can identify the exact cause of the allergy, eliminate it and continue to live a full life. So, there is such a thing as a panel of food allergens. The essence of the study is described below.
Allergy Concept
First you need to understand what a food allergy is. This is an incorrect reaction of the body to any foreign protein that is found in many food products.
The mechanism of the development of food allergies is as follows: during initial contact with any foreign protein contained in food, a sensitization reaction develops on the gastrointestinal mucosa. Then, when the protein enters the body again, enhanced synthesis of immunoglobulin E begins, which affects the synthesis of histamine, an organic substance. It provokes the development of allergy symptoms:
- Increasing the permeability of the capillary walls, provokes tissue edema.
- Causing muscle spasm can cause respiratory arrest.
- Reduces pressure in arterial vessels.
The second name of this pathology is allergic gastroenteritis, the symptoms of which can be studied in the next chapter.
Panel of food allergens. Indications
Like any other disease, food allergies are not asymptomatic. On the contrary, they usually do not have to wait. Moreover, sometimes the symptoms appear quite pronounced:
- Nausea, vomiting.
- Pain in the stomach.
- Bloating.
- Violation of the stool.
- The appearance of an itchy rash on the skin.
- With a pronounced allergic reaction , the occurrence of Quincke's edema, urticaria can occur.
In children under the age of one year, the characteristic symptoms will be:
- The presence of persistent diaper rash, which does not go away even with careful skin care of the baby.
- The appearance of irritation around the anus. In boys, the tip of the penis may also redden.
- The baby becomes restless, sleeps poorly and cries a lot.
All this can serve as a reason for going to the doctor and donating blood for analysis. A panel of food allergens is the name of the method for diagnosing allergies.
The essence of the analysis
The analysis is an immunoblot, a supersensitive method for identifying certain proteins.
During this analysis, special nitrocellulose membranes are used, and strips of various specific proteins are applied to them in a row. If, when in contact with the blood, a streak darkens, it can be judged that the patient has an allergic reaction to a particular product.
Advantages of the method
The food allergen panel is one of the most reliable methods and has several advantages:
- Accuracy. The interval of the obtained values is very wide, therefore it allows you to decrypt the result as accurately as possible.
- High speed. After passing the analysis, he is ready, as a rule, the very next day.
- High degree of information. Gives an idea of how a particular person's body reacts to a number of allergic proteins.
- The reliability of the results.
- Lack of contraindications.
What is included in the allergen panel?
This list consists of twenty items, namely:
- Animal products: cow's milk, eggs, casein.
- Fish and seafood: cod, crab, shrimp.
- Nuts and seeds: sesame, peanuts, walnuts, almonds, hazelnuts.
- Cereals: wheat flour, rye flour.
- Fruits, vegetables and greens: apple, citrus fruits, tomato, carrots, potatoes, soybeans, celery.
This is the standard list of products for which the patient is allergic. It is worth noting that in laboratory diagnostics there is also an expanded panel, which includes about 90 points. They resort to it if necessary, which occurs in cases where the search for an allergen is difficult.
Who can take this analysis?
Both adults and children can donate blood for allergens. The food panel of allergens for children is called pediatric and is somewhat different in the list of foreign proteins, but the essence of the method does not change from this.
It is worth saying that the earliest age for this examination is 2 years and only as prescribed by the pediatrician or allergist. Nevertheless, if necessary, it can be carried out in very young children.
How is this analysis
In the morning, on an empty stomach, the patient should come to the laboratory, where a specialist will take his blood from a vein at the elbow.
An analysis requires about 5-10 ml of biological material. After that, the serum will be separated from the blood in the laboratory. It will search for foreign proteins that act as antigens for the human body (the second name is triggers).
Analysis preparation
When donating blood to allergens, you should always remember that accurate and reliable analysis results will be obtained only if you properly prepare for it. Therefore, it is very important to study the following points in detail and try to adhere to them:
- Before the laboratory technician takes the blood, the patient should not eat anything for at least eight hours. It is allowed to drink a small amount of clean drinking water. If the patient is a baby, you can not feed him at least three hours.
- An adult needs to check his diet for two days before the analysis and make sure that it does not contain too fatty foods (cottage cheese, sausages and the like). Otherwise, chiles may occur - a process in which serum contains lipids and it becomes cloudy, which makes the analysis difficult or impossible.
- It is necessary to donate blood in the early morning hours (the latest - at 11.00)
- On the eve of the analysis, you should try not to use any biological active additives and medications. If this is not possible, then it is necessary to warn the attending physician about this in advance. The fact is that some tools can affect the results of the analysis, which makes it meaningless.
Decryption analysis
The result is measured in Ig3, Ig4. The value can be in the range from 0 to 100. Moreover, there is a pattern - the higher this number, the stronger the patient's body responds to the allergen. Depending on the data received, they are divided into several categories:
- ≤0.34 - absolute absence of reaction;
- 0.34-0.79 - a very weak or weak reaction;
- 0.8-3.9 - there is a food allergy;
- 4.0-16.9 - there is a very pronounced reaction;
- 17.0-100.0 - a very strong reaction of the immune system to the allergen. In this case, there is even a chance of death (in the form of edema of the respiratory tract).
Procedure cost
This analysis belongs to the category of paid. Therefore, everyone to whom the doctor prescribed this examination wonders how much it costs to carry out a food panel of allergens. Invitro (one of the most famous diagnostic laboratories) currently estimates the analysis at 4535 rubles (relevant for Moscow). The pediatric panel has a similar cost.
In addition, in the organization’s price list there are analyzes for a specific mixture of food allergens. For example, only kiwi, apple, peach, banana. Or another set - pork, beef, chicken, lamb. The cost of such sets is lower and equal to 1700 rubles.
In fact, the food panel of allergens is not the most expensive analysis for this pathology. For example, in some diagnostic laboratories there is such a test as the immunoCAP allergochip, during which the body's response to 112 allergens is studied. The approximate cost of this procedure is about 25 thousand Russian rubles.
It should be noted that the final price of these tests depends on the region, city and specific diagnostic laboratory.
Reviews
The panel of food allergens in the vast majority of cases has a positive response.
The main advantage that patients especially highlight is the fast speed of obtaining results, which is very important. After all, allergy symptoms are sometimes simply unbearable, and antihistamines (based on desloratadine, cetirizine and the like) can eliminate the malaise for a maximum of several hours.
If we study the reviews on the pediatric panel in detail, we can conclude that often mothers note that their young children can hardly endure for a long time without food. Therefore, the child needs to be distracted in every way until the moment when blood from the vein is taken from his vein, and then immediately feed.
The main disadvantage of this diagnostic method, of course, is its high cost.
In addition, there are cases when the results of the analysis are not quite true. Almost always, this can be explained by insufficient or incorrect preparation of the patient for analysis.
Conclusion
The food allergen panel (blood test) is a unique method for laboratory diagnosis of an allergic reaction. It can be used in both children and adults and has a number of advantages.
However, do not forget that for a high-quality analysis and reliable results, the patient must carefully prepare for the procedure. This will help to avoid many problems, such as repeated blood donation, excess spending of money or prescribing by the doctor the wrong treatment, which will not bring relief.