The Mantoux reaction is a provocative test, the purpose of which is to identify specific immunity to tuberculin. It is done at any age to diagnose tuberculosis and to check the effectiveness of treatment.
Tuberculin is a purified extract of killed tuberculous bacteria. A person is found to have 2 TE (2 tuberculin units in 0.1 ml of a standard solvent) intradermally. Normally, immediately after the injection, a "button" should form - a small bump on the skin, which is slightly lighter than the rest of the skin. It should dissolve on its own in 20 minutes. For some time it should not be touched, scratched and rubbed with a washcloth. You can wash.
The reaction is taken into account on the third day. Measure the transverse dimension of the reaction with a transparent ruler. Consider the presence of infiltration, hyperemia and other possible reactions. Testing is compulsory for all children and is regulated by the Decree of the Chief State Sanitary Doctor of the Russian Federation dated 10.23.2013 No. 60 "On the approval of sanitary and epidemiological rules of SP z.1.2. 3114-13" Prevention of tuberculosis ".
Goals of universal tuberculin diagnosis:
- Early detection of the initial forms of tuberculosis in children and adolescents from one to 18 years of age;
- Selection of children and adolescents who require consultation with a phthisiatrician;
- Selection of children without tuberculosis protection.
The refusal of the child's legal representatives to check him for tuberculosis according to the law may lead to the fact that the latter may be banned from visiting a child care institution if a certificate from a phthisiatrician about the absence of tuberculosis is not provided within a month. Those. in any case, you will need to visit the tuberculosis dispensary (if there is no phthisiatrician in the children's clinic), where the child will be sent for a blood test, they will offer to put the Diaskin test, take a snapshot of the lungs. Then they will offer to come back for examination after three days to take into account the reaction. Tuberculosis dispensaries conduct a general appointment, where a child sent for hospitalization will sit in line along with a healthy child. Therefore, it is easier to immediately make a Mantoux in a clinic or childcare facility.
The Mantoux reaction is not given:
- If you have recently done BCG;
- If a person is sick or has recently suffered from ARVI;
- If previously there was hyperergia after Mantoux.
- Less than a month has passed since the vaccination against childhood infections.
Preparing for the production of Mantoux
It is believed that the Mantoux reaction is slightly reactive, but doctors recommend that children with frequent allergic reactions and atopy take antihistamines three days before and after the Mantoux test. This does not affect the results of the reaction accounting, since the reaction is based on delayed-type hypersensitivity, which depends on the presence of antibodies.
- Local - occurs at the injection site. It is characterized by hyperemia, infiltration, papule formation.
- General reaction. Possible weakness, deterioration of health, low-grade fever, exacerbation of any chronic disease.
Focal reaction. Changes appear in the focus of tuberculosis, if any.
Consideration of local reaction and size of skin reaction
- Negative reaction - (anergy) - the skin at the injection site is clean;
- Doubtful - there is an infiltration (edema) of 2-4 mm in size or only hyperemia of any size;
- Positive - infiltration of 5 mm or more. 5-9 mm - a weakly positive reaction, 10-14 - a reaction of medium intensity, 15-20 - a pronounced reaction;
- Hyperergia - 21 mm or more, vesiculo-necrotic reaction;
An intensifying reaction (bend) - an increase in edema by 5 mm or more in comparison with the result of the previous year.
Children who have not received the BCG vaccine for more than five years (or have not been vaccinated at all) should not react to tuberculin. 72 hours after the test, there should be no redness and infiltration on the skin.The lack of reaction - anergy - indicates that the body has not previously encountered tuberculosis, did not recognize it, and there are no protective antibodies in the body. If, after a year, an increase in infiltration of more than 5 mm is recorded, then doctors believe that there has been a turn or contact with mycobacterium tuberculosis.
Based on the doubtful and positive reaction to the Mantoux test, one can suspect the presence in the body of mycobacteria that cause tuberculosis. The patient is sent to the TB dispensary, where the doctor prescribes a set of diagnostic procedures to confirm the result:
- Snapshot of the lungs;
- Blood analysis;
- Diaskin test;
- Culture of sputum from the lungs;
- Sometimes tomography is done.
Hyperergia requires an immediate visit to the dispensary. It should be borne in mind that even infected children may have anergy during remission or recovery from tuberculosis, which indicates a positive dynamics of the disease.
Some children do not develop good immunity to tuberculosis after the first BCG vaccination - they often have no scar at all on their left shoulder, where BCG was injected in the first days of life. In the TB dispensary, such children will be immediately noticed if they have a dubious reaction. If the reaction after Mantoux is negative, then they need to be re-vaccinated at 7 years old. Approximately 2% of people do not have a reaction to BCG, they are not genetically susceptible to tuberculosis and BCG will be perceived by the body as an ordinary injection, mycobacterium tuberculosis will not multiply and cause an immune response in the body.
Normally, after BCG, the vaccination site will be hyperemic, it can fester many times, the axillary lymph nodes will be enlarged - this indicates high cellular immunity. In newborns, this reaction develops about a month after the introduction of the vaccine strain. At the age of 7, when the revaccination is in progress, the same symptoms of inflammation will be observed. While the infectious process is underway, the test for tuberculin will be positive. Sometimes, illiterate medical personnel immediately send them to a tuberculosis dispensary with such a reaction.
After vaccination, the Mantoux test will be positive for a long time, since the BCG strain will circulate in the body, this is normal. After vaccination and revaccination for 2-3 years, the reaction will be positive and this indicates the normal development of immunity.
Unfortunately, often the general reaction to the tuberculin test is not taken into account. Feeling unwell, remission of any diseases, the same bronchitis, or a relapse of an autoimmune disease can sometimes indicate the presence of an active tuberculous process in a person. Moreover, the Mantoux reaction itself may be questionable if the immune system is weak. Therefore, one must be very attentive to the child after the tuberculin test. Tuberculosis can be in any organ, and the test can aid in the diagnosis. One should be afraid not of the cliché that the child is sick with tuberculosis, but of the consequences of this disease. It is easier to get treatment and continue to lead a fulfilling life than to suffer from lupus or multiple sclerosis later.
Mycobacterium species causing tuberculosis
The infectious process in humans can be caused by various mycobacteria. Most often caused by M. tuberculosis strains in 92% of cases, M. bovis - 5% and M. africanum - 3%. The latter is less common in central Russia. M. tuberculosis is an anaerobic, it feels great in the lungs, while other strains can survive without oxygen and infect any internal organs and tissues. Therefore, a snapshot of the lungs does not always help diagnose tuberculosis. The tuberculin test reveals the process caused by any mycobacterium. To confirm the diagnosis and differentiation of the pathogen, they also do the Diaskin test. It identifies the process caused by human tuberculosis, which is considered to be more virulent.