Perhaps today it is impossible to name a second, as common disease as an allergy. This was far from always the case, but in modern conditions, the human body constantly experiences a great many adverse factors. As a result, in the normal functioning of the immune system, a failure occurs, which turns into the development of an allergic reaction.
The best way to treat allergies is to distance the patient from the source of the allergy. In some cases, the patient himself, based on the reaction of his body, upon contact with certain substances, is able to recognize which of them causes allergy symptoms. But this happens, alas, not always. In such cases, special diagnostic measures are needed to identify the substances that provoke allergies.
Skin tests
Skin tests are a method for diagnosing the sensitivity of an allergic organism by introducing a specially prepared allergenic material into the epidermis in order to monitor the reaction of skin sensitivity. The epidermis contains both antibodies, cells that produce histamine, and cells that are sensitive to its effects, that is, all the components that are necessary for the manifestation of allergy symptoms, if this type of sensitivity is characteristic of the body.
The sensitivity of the epidermis to an allergen makes it possible to diagnose, using skin tests, allergies of various types: food, pollen allergy, drug allergy, dust mite allergy, etc. The amount of allergenic material that is introduced into the space of the skin is extremely small. Skin tests are carried out in various ways:
Skin test by scarification method
The essence of this method of conducting skin tests is to apply with a special device, minimally invasive incisions, into the cavities of which specially prepared allergen components are introduced. The main places for scarification tests are: forearm, back and shoulders. The results often become noticeable after 10-15 minutes, in rare cases, they can appear after a few days.
Skin prick test
A skin prick test is a small amount of the allergen that is injected into the skin with a syringe. This method is distinguished by the greatest sensitivity, since in this case, the allergen penetrates into the blood in the best way and, accordingly, causes the corresponding immune responses with the greatest efficiency.
Skin test by application method
For this method, as a method of introducing an allergen, an application dressing is used, which is impregnated with a solution of allergens. This method works best to detect contact type allergens. These are allergens that cause skin manifestations when in direct contact with this organ. In order for the application tests to give an adequate result, it is not recommended to engage in physical activity during the application of the bandage, and also not to contact with water and other liquids. The bandage is kept on the skin for several days, after which the condition of the skin is diagnosed.
Provocative tests
Provocative tests are diagnostic measures in determining the typology of an allergen, which are based on the contact of a sensitive organ with a hypothetical allergen. In no case should provocative tests be carried out in case of exacerbation of symptoms of an allergic disease. Provocative tests differ depending on the organ that is exposed to contact: intranasal, inhalation, ocular, etc.
Provocative diagnostic methods are indicated if skin tests did not give a positive result, but there are significant suspicions of an allergen that did not cause skin sensitivity. Due to the direct contact of the patient with the allergen, which is necessary for provocative diagnosis, it is not carried out during an exacerbation of an allergic disease.
An eye provocative test is carried out by introducing an allergen solution, for conjunctival use, in the presence of allergic conjunctivitis of unknown origin. A special solution with an optimal acid-base index (7.0) is injected into the lower part of the eye. If the initial concentration is insufficient to provoke sensitivity, then twice the concentrated mixture is injected into the other eye.
After an allergic reaction, an adrenaline solution is injected into the eye, as well as antihistamines and corticosteroids to stop the positive result of provocative tests.
Intranasal tests are a method of introducing an allergen into the nasal sinus, with allergic rhinitis of unknown etiology. A nasal allergen solution is dripped or sprayed. Intranasal tests should never be carried out during an exacerbation of an allergic reaction. Symptoms of allergic rhinitis or bronchial asthma occurring after 10-20 minutes are considered positive results.
Skin and provocative tests are not performed:
- In case of exacerbation of the symptoms of the disease;
- In pregnant women, the elderly and children;
- While taking antihitsamine and corticosteroid drugs
When conducting skin and provocative tests, strict medical supervision is necessary, since they involve the direct penetration of the allergen into the body, which can lead to the development of severe forms of allergic complications. In no case should you experiment with allergic diagnostics on your own.
General blood test for allergies
Blood is a tissue of the body that performs a transport function. It nourishes every organ of the body and is in close contact with all other systems. This allows you to monitor the state of health according to the state of the blood. With allergies, in addition to the general indicator, there are special signs that are expressed by an increase in the level of eosinophils. Eosinophils are cells that are involved in the production of antibodies. Allergic reactions often disappear with an increase in the level of eosinophils in the body.
Blood test for antibodies
Symptomatic manifestations, as well as patient complaints, are not the only way to diagnose allergies that modern medicine has. Among these methods, an honorable place is occupied by blood tests for the concentration of antibodies, since the diagnosis is carried out outside the patient's body, but in laboratory conditions, which implies the complete safety of this method for the patient. Modern blood tests for antibodies make it possible to determine not only the presence of an allergic disease, but also the nature of the allergen that provokes it.
For this event, venous blood is taken from a patient with allergies. Obtaining blood material is carried out, without fail, on an empty stomach. The blood obtained as a result of sampling is subjected to contact with solutions of alleged allergens. Allergic material entering the blood leads to an increase in the level of general and special antibodies. Antibodies are special body proteins designed to bind to allergens. This complex provokes the release of histamine, which causes allergy symptoms.
Allergy symptoms
In terms of diagnosis, allergy symptoms are very indicative, since they allow you to determine the further direction for diagnosis. Allergy symptoms are a disparate group, which is combined according to common features. Diagnosis of allergies should be carried out taking into account the similarity of its symptomatic picture with helminthic invasions, which have similar symptoms.
Allergic dermatitis
As the name implies, allergic dermatitis is a group of symptoms that include specific skin manifestations of allergic reactions. Symptoms of dermatitis can occur not only as a result of direct skin contact with an irritant. They are also common in food and drug allergies.
In the development of symptoms of allergic dermatitis, in addition to histamine, factors such as cytokines and eiconazoids play an important role, the migration of which to the localization of an allergic reaction takes a long time. For this reason, the development of an allergic reaction does not take place immediately after an allergy has been ingested. In general, it takes 6 hours or more for the symptoms of allergic dermatitis to appear.
For the development of contact dermatitis, a certain amount of time is required for the interaction of the allergen with the skin, since with short-term contact, the allergen substance is not able to penetrate the skin to provoke allergy symptoms.
Allergic dermatitis is manifested by the formation of an inflammatory reaction, the formation of blisters and erosion, filled with a transparent or serous substrate, a yellow or brown crust. The areas of localization of allergic dermatitis often itch very strongly, when combing, dermatological symptoms increase. Most acutely, the symptoms of dermatitis appear in early childhood. They can occur as a result of the abrupt introduction of natural products, after breastfeeding. Often, the symptoms of dermatitis that appear in this case are reversible.
Allergic conjunctivitis
This symptomatology implies allergic manifestations affecting the eyes. They are characterized by: redness, vasodilation of the eyes, swelling and inflammation of areas adjacent to the eye, increased sensitivity to light, pain in the eyes. Symptoms of allergic conjunctivitis occur as a result of allergens entering the sensitive mucous membrane of the eye. They often occur when allergic to plant pollen.
allergic rhinitis
Allergic rhinitis is an inflammatory symptom that affects the nasopharyngeal region. For this disorder, manifestations of swelling of the nasal sinuses, local expansion of the vessel, runny nose, itching and irritation of the nose, and frequent sneezing are characteristic.
Allergic urticaria
This symptom of allergy is manifested by the appearance of red spots that resemble burns obtained when the poison contained in nettle leaves comes into contact with the skin. For urticaria, a characteristic sign is an increase in temperature, in places of manifestation of an allergic reaction. Urticaria foci tend to merge, as a result of which the patient's general temperature may increase to 38 degrees.
Allergy does not occur at the first contact with the allergen. In any case, for its occurrence, sensitization of the body is necessary, as well as repeated exposure to the allergen. This disease is associated with a violation of the immune system, which is expressed in the development of pathological reactions of the immune response to certain stimuli. The occurrence of these reactions is due to a special mechanism during which protein antibodies are produced that are complementary to certain areas of the allergens.
Further, under the influence of an immune complex consisting of a soldered allergen and an antibody, the release of histamine by mast cell membranes is manifested. This hormone is able to act on epithelial cells, as well as mucous membranes, provoking symptoms of allergic reactions. At the first signs of allergy symptoms, you should contact an allergist who specializes in the diagnosis and treatment of allergic diseases. Self-diagnosis and treatment of allergies threatens with a high degree of risk in relation to severe allergy symptoms.
