"Diaskintest": reviews. "Diaskintest" in the diagnosis of tuberculosis

Diagnosis of tuberculosis is being improved more and more. The old methods are replaced by new, more accurate and perfect ones. They can include a diaskintest.

What it is?

Diaskintest - a reaction that is somewhat similar to the Mantoux, but more sensitive to the human mycobacterium tuberculosis. Like the Mantoux reaction, it is used mainly in children, although in some cases it is also shown to adults.

The methodology has been relatively new. The stimulus to its creation was that the Mantoux reaction did not give precise information as to the antibodies to which strain of mycobacteria are present in the body (since it determines sensitivity to two subspecies, human and bovine mycobacteria).

The specificity of the injection is almost 90 percent, while the sensitivity of the sample with tuberculin does not exceed 50. Because of this, the occurrence of false and incorrect results is high.

It is necessary to understand how the diaskintest is carried out, and also to determine the contingent to whom this reaction is shown.

How is the procedure performed?

Diaskintest itself, whose reviews are currently predominantly positive, do not differ in any way from the Mantoux reaction. The sample is placed on the inside of the forearm. The needle is inserted intracutaneously for several millimeters. After the introduction of the drug at the injection site, a papule with a "lemon peel" surface is formed. After a while (usually after two days) an evaluation of the formed papule is carried out.

Diaskintest for tuberculosis is mandatory in specially equipped rooms or treatment rooms. It is forbidden to inject at home, as well as unprepared personnel without the created conditions of sterility. This can lead to complications after the procedure.

To determine the results of the study, assess changes in the area where the diaskintest was conducted.

Evaluation of test results is carried out according to certain criteria. If a negative result is obtained (none of the criteria is identified), the study is repeated or sent for further examination to specialized institutions.

What signs are used to assess the effectiveness of the procedure and the state of health?

Criteria for evaluation

After the diaskintest was carried out, the results are evaluated by the presence of changes in the injection zone.

Normally, a hyperemia zone should form at the site of injection. Its appearance is due to an increased inflow of blood to the injection site, as well as local allergic reaction.

The size of the papule depends on the degree of immune response. The larger the diameter of the formed papule, the stronger the reaction of the immune system. However, too small or, on the contrary, an excessively large size of the papule are unfavorable signs, since they indicate a weakened or overly active immune system and its response to the introduction of foreign antigens.

In addition, the formed papule is compared with previous results, determining the dynamics of changes. If there is a positive reaction to the diaskintest, the photos and dimensions of the papule must be compared with the previous results. It is possible that for a given period of time (a year since the last reaction), a person has had contact with a sick tuberculosis. In this case, a comparison with past results is required.

Diaskintest for tuberculosis is considered to be carried out according to all rules and norms, if there are two of the above criteria.

Interpretation of results

How can we judge the presence of antibodies to mycobacteria?

Diaskintest evaluation is carried out according to two criteria: redness in the area of injection and size.

If there is no hyperemia zone at the injection site, this indicates that either the procedure was performed incorrectly or the immunity is so weak that it can not respond to the administration of antigens. This is also indicated by the absence of a papule at the injection site.

If there is hyperemia, and the papule is small (up to 4 mm), a weak immune system is judged. A similar result can also say that there are very few antibodies, and the organism can not cope with it if it gets into it.

What is the result of a healthy person with a diaskintest? Its norm is from 4 to 12 mm, which indicates the normal function of the immune system and the presence of necessary antibodies.

If suddenly a papule larger than 12 mm is formed at the injection site, this indicates the hyperreactivity of the immune system, i.е. In response to the penetration of the mycobacterium, an allergic reaction may develop.

However, it should be remembered that the results in adults and in children may differ somewhat from each other. In adults, who received a diaskintest, the norm will be somewhat larger - from 4 to 16 mm. This phenomenon is observed due to the fact that the body of an adult human antibodies more than a child. Some of them can be activated in the presence of antigenic mimicry - the antigen of the mycobacterium can be recognized as a foreign protein of another microorganism, and in response to this, other cells may activate, which will somewhat strengthen the allergic reaction.

Sometimes the absence of a papule or its large size may indicate that the procedure is not performed correctly. One more must be done for clarification. If the result is repeated (repeated negative or positive dyskintest), the phthisiatric consultation is indicated.

The surveyed contingent

Who is shown the procedure?

This study is mandatory for children under 17 years. This is because the main method of screening tuberculosis - fluorography - is associated with X-ray radiation, which can affect the development of the child's body. That is why preference is given to the introduction of antigens, rather than irradiation.

Injection is given to children approximately six months after the introduction of the BCG vaccine. During this time antibodies to antigens of mycobacteria have time to form, which makes the study expedient.

In addition, it is necessary to conduct a procedure for people who are registered with an endocrinologist for diabetes.

All without exception, a diaskintest is performed if there are significant changes in the papule in comparison with the previous study (the procedure is carried out once a year, but it is possible to carry out an investigation up to 3 times unplanned).

Positive diaskintest is often determined by people serving sentences (in prisons, colonies), so they have a survey several times a year.

Indications

Diaskintest, like the Mantoux reaction, is a purely diagnostic procedure aimed at mass monitoring of tuberculosis development in childhood.

Usually this research is done on a routine basis, but there are some indications for its extraordinary holding.

As such predisposing factors are the turn of the Mantoux reaction, a significant change in the formed papule in comparison with the previous results. In children with a long (more than a month) subfebrile condition and the presence of a dry cough, a repeated examination, including a diaskintest, should be carried out. Photo of the chest (fluorogram) in this case is done with the permission of the child's parents and used to clarify the diagnosis.

In addition, the study is mandatory in children and adults with diabetes (since this disease provokes the development of immunodeficiency, facilitates the penetration of the pathogen into the body and the development of the infection process).

It is necessary to carry out an unscheduled test for children whose parents have been diagnosed with tuberculosis.

Contraindications

Like any procedure, a diaskintest has some contraindications to the conduct. These include increased sensitivity to the components of the drug, as well as the presence of an active infectious process in the study area (diaskintest is somewhat limited in use, since the injection is carried out on the forearm, where the skin is rather thin, which allows the formation of papules. Always it is possible to obtain the necessary results).

There is also some age restriction. The procedure is not carried out for newborns and children who have not previously been vaccinated with BCG.

With care, the study is conducted for people with the presence of immunodeficiency, since the introduction of antigens can provoke an incorrect response of the body.

Advantages of Diaskintest

As is known, the diaskintest came to replace the Mantoux reaction. This was due to the fact that the Mantoux reaction does not give exact results with respect to antibody formation against the human mycobacterium tuberculosis (determines the presence of antibodies against two strains of mycobacterium). Diaskintest, phthisiatric reviews about which are mostly positive, is a more narrowly focused procedure, since the injected drug contains only antibodies m. Tuberculosis.

There are isolated cases when, following injection, the Mantoux reaction developed active tuberculosis. In the epidemiological plan, the diaskintest is safer, since it does not contain active mycobacteria, but only their antigens that promote antibody formation. The hypersensitivity reaction practically never develops upon administration of the drug.

Since the procedure is no different from the standard tuberculin diagnostics, most trained procedural sisters can conduct it.

Opinions of patients and doctors

For a short time that used a diaskintest, he received a considerable amount of feedback from both patients and doctors.

When examining most of the forums where patients, tuberculosis patients or their relatives who have been given a disaskintest communicate, the reviews were in most cases positive. According to people, the procedure is fairly simple to implement, does not require any training from them.

What do doctors think about this issue? Many phthisiatricians tend to argue that the diaskintest is a more versatile procedure than the Mantoux reaction or Pirke's skin test (not currently used). High specificity of the drug makes it possible to confirm with almost absolute certainty the presence of mycobacterium in the body and start treatment in time. Many people are encouraging patients to prefer not a fluorogram (which allows us to identify only the disease itself), but passed a diaskintest. The doctors' comments about the procedure are almost always positive, only a small part of them prefer radiography or Mantoux.

Where can I go through the procedure?

If you have a suspicion that you have tuberculosis, it often raises the question of where to turn. Such thoughts usually appear after the radiologist has noticed a shadow in the picture of the lung, or you cough for a long time, feel weak and broken. All this indicates a possible presence of active tuberculosis, and you can not hesitate with the diagnosis.

In the first place, a diaskintest can be performed in specialized institutions - tuberculosis dispensaries or polyclinics. Usually the procedure is carried out by all comers for a fee, although it is possible and even necessary to go there and in the direction of the district therapist.

In addition, to conduct this procedure, you can contact the regional health centers (for example, district hospitals) or sanitation. Usually there must be at least one phthisiatrician on the district who can correctly examine you and, if necessary, diagnose tuberculosis with a diaskintest.