Tuberculosis is a fairly common infectious disease that can be found literally in any country in the world. The disease can occur due to the ingestion of various bacteria or Koch's bacillus. The disease is most often transmitted by airborne droplets and has severe symptoms, namely:
- dizziness;
- wet cough;
- hemoptysis;
- weakness;
- febrile condition;
- unreasonable weight loss;
- night sweats.
Tuberculin tests are contraindicated in the presence of various skin diseases, allergic reactions, bronchial asthma, epilepsy, infectious diseases. It is not necessary to do tests within one month after the injection of immunoglobulin or a biological sample.
Tuberculosis Diagnosis
The main organ that is damaged by tuberculosis is the lungs. Other internal organs rarely suffer from this disease. It is possible to diagnose tuberculosis with the help of fluorography, CT (computed tomography), radiography, tuberculin skin test (Pirke test) and other types of laboratory tests. FROMfor the purpose of diagnosing the disease, vaccination is carried out once a year.
What is a skin test reaction?
One of the methods of preventive examination of children for tuberculosis is the Pirquet test. This immunological test is able to show whether a growing organism, even in the early stages, has a tuberculosis infection. The reaction of the body to the appearance of tuberculin is called the Pirquet reaction, and it determines the sensitivity of the body to Mycobacterium tuberculosis. The pirque test is also done in patients of the already adult age group as a control analysis when evaluating the effectiveness of treatment.
Sample composition
The sample contains tuberculin - a special extract from the destroyed Koch bacilli, invented back in 1890 by the German doctor Robert Koch. It was this doctor who became the discoverer of such a disease as tuberculosis. The hood began to be used in 1907. Initially, they lubricated the skin with it and monitored the reaction, and after that they began to try to inject tuberculin subcutaneously.
Today, the Pirke test, the composition of which includes a mixture of killed culture filtrates of human and bovine microbacteria, is observed in many people of different age groups. In addition to the active main substance - tuberculin Pirquet, the sample includes the following additional substances:
- phosphate buffer s alts;
- sodium chloride.
How is this happening?
The principle of the test, the composition of which is based on tuberculin,consists in the skin application of the drug. The skin of the forearm or shoulder is well disinfected only with carbolic acid, because alcohol-containing substances leave protein on the skin, which is undesirable for the purity of the analysis. Notches on the skin are made using a scarifier with a depth of not more than 5 mm. The patient must wait up to 5 minutes until the solution is absorbed, and the residue is gently wiped off with a paper towel. After the procedure, the patient is monitored for 48 hours and the reaction to the substance is analyzed.
As a result of the introduction of tuberculin, a specific inflammation (papule) occurs at the site of scratches, which is provoked by the accumulation of T-lymphocytes. It is these blood cells that are responsible for anti-tuberculosis immunity. The skin can change color and density in the area of the papule. This method of diagnosis is used quite rarely due to its low information content and low diagnostic efficiency. After the test has been made and until the results are obtained, it is not recommended:
- wetting the place where the sample was taken;
- wipe the papule with various drugs or ointments;
- stick the papule with a band-aid;
- comb or tear.
Results
On average, when the Pirquet test is performed, the results are evaluated after 2-3 days, that is, 48-72 hours. At the place where the scratches were made, a focus of irritation appears. His area is measured by doctors. The results are classified in this way when the test is performedPirque:
- the norm is observed with a minimum measurement of papule (up to 5 mm on average);
- 3 mm indicates the need for re-vaccination and re-analysis of the result of irritation;
- if a papule is found ranging in size from 4 to 10 mm, then this means a possible infection with tuberculosis or a person at risk (that is, constant contact with an infected person);
- if the focus of irritation is 10 to 15 mm in size or ulcers are found at the vaccination site, then this indicator indicates a high probability of infection with tuberculosis.
Graduated sample
This type of study has been improved and is a skin application of the drug with a few scratches. Unlike the traditional version of the study, a graduated test allows you to determine the differential diagnostic value in the process of clarifying the nature of an allergy to tuberculin. A skin test is carried out by applying tuberculin to the skin with 100%, 25%, 5% and 1% concentration. Skin preparation is carried out in the same way as in the traditional Pirquet test. Notches are applied strictly in order, and various marked pipettes are used. Only sterile materials are used for each patient. After the appearance of a "white roller", the remnants of tuberculin can be removed. This type of diagnosis is most often carried out in order to determine the effectiveness of TB treatment.
Graduated sample results
Grinchar and Karpilovsky graded skin test is evaluated after 48-72 hours after the procedure. There are such reactions of the body to various concentrations of tuberculin:
- anergic reaction (no reaction to samples);
- non-specific reaction (only slight redness can be seen on a sample with a 100% solution concentration);
- normal reaction (there is a moderate reaction of the body to tuberculin, and there are no reactions to samples with a 5% and 1% solution);
- hyperergic reaction (this result is characterized by a response to all types of samples; the higher the concentration of tuberculin in the solution, the greater the reaction);
- equalizing type of reaction (all samples taken have the same papules, skin colors and sizes of foci of inflammation);
- paradoxical reaction (with a higher concentration of tuberculin in the sample, a more pronounced reaction is observed).
So, we have considered such a diagnostic method as the Pirquet test. Its result does not indicate the localization of the disease in the body or the ability of a person to infect he althy people. It indicates only the reaction of the body to the causative agent of tuberculosis. The Pirquet test (Mantoux reaction is its alternative) is considered mandatory for children.
