What size should Mantoux be? Dimensions of Mantoux: norm and deviation

In the fight against the mass vaccination campaign, many people simultaneously refuse Mantoux tests. But this small injection has nothing to do with vaccination. In this way, doctors simply check how immunity reacts to the introduction of tuberculin. Normally, a small inflammatory process should develop. To understand the reaction of the body, it is necessary to know what Mantoux dimensions should be. The norm is set depending on the age of the baby and the timing of the introduction of the BCG vaccination.

To whom and when do Mantoux

Basically this method checks the health of children. Even in the first days of life, a newborn is vaccinated - BCG, it is she who is responsible for the formation of anti-tuberculosis immunity. If the timing of the introduction of the vaccine has not been violated for some reason, the first Mantoux reaction is done in one year.

If the baby was not vaccinated in the maternity hospital or in the first month of life, a tuberculin test is performed before BCG to exclude the disease. Many are wondering what size Mantoux should be in a child without this vaccination. If the immunity of the baby is not familiar with tuberculosis, then there should be no reaction. Usually, the place of administration of the drug in a healthy and unvaccinated baby does not cause redness or densification.

Risk group

Many parents refuse from tuberculin tests, motivating their position by the fact that there are no patients in their environment. But many do not even suspect that it is very easy to get infected. If you are visiting public places with a child, whether it is a kindergarten, developing circles, a school, theaters or exhibitions, you go to visit and use transport, in which other people go, then you expose your child to danger.

Being in the community, you run the risk of meeting a sick tuberculosis, who probably does not even know about his illness. Take into account: in the lungs of any adult there are mycobacteria of this disease. While immunity is able to contain them, there will be no problems. But as soon as provoking factors appear, the disease will begin to develop. That is why it is so important to make a test for tuberculosis on time and know what Mantoux size should be.

Response to the administration of

Everyone knows that the result of a tuberculin test is estimated seventy-two hours after the injection. At the injection site on the second day, a so-called button or infiltrate is formed. It looks like a small bulging papule of a reddish color. If you press it down with a transparent ruler, you will see how it turns pale. It is this solid area that must be investigated, because it shows the dimensions of Mantoux. The norm of this reaction depends on when the child was made BCG.

Many do not know why they inject tuberculin. This study allows you to determine whether Koch's rods are present in the body. It can also show the period of activation of the infection and confirm the diagnosis of "tuberculosis".In addition, it can help identify children who are completely immune from this disease.

Established norms

In our country it is customary to do BCG in the maternity hospital, and the first injection of tuberculin is a year. Previously, it does not make sense, because the result can be distorted. To understand if your child has problems, you need to figure out what Mantoux size should be. A test is considered negative if after 72 hours only the injection site is visible, and there is no infiltration at all. With a papule 2-4 mm in diameter or redness of any size, the result is considered doubtful. If the infiltrate is within 5-17 mm, then this is considered a positive reaction. At the same time, it is subdivided into medium - five to nine, intensive - ten to fourteen, and clearly expressed - in excess of fifteen millimeters.

If the Mantoux size in children exceeds 17 mm, or if there are bubbles, necrotic zone or lymph nodes in the area of ​​the injection, this is called a hyperergic reaction, for adults this limit is 21 mm.

Rules for evaluating the result of

For an adequate understanding of the situation, it is important to know that a negative test is only in the absence of immunity to tuberculosis. If a child has BCG, and there is no reaction to tuberculin, then the vaccine does not work, it is advisable to make a revaccination. If the baby is first made a Mantoux reaction, its size can be quite large. If no more than two years have elapsed after the vaccination, it should be positive - this indicates an adequate response of the body to BCG.Please note that the baby should always have a hem at the injection site. If it is not, and Mantoux is positive, then it indicates the infection of the body.

Two years after vaccination, the size of the infiltrate should decrease. As a rule, it disappears completely by seven years. Just at this time re-inoculation of BCG is carried out, with its help reinforce immunity. Reducing the size of the "button" indicates that, most likely, there was an infection.

Virage sample

When figuring out what Mantoux size should be, it is important not only what the ruler will show, but also how this indicator varies from year to year. Thus, the following situations are referred to as a tubular test:

- the first occurrence of a positive Mantoux, provided that the previous results were less than 5 mm;

- the difference in size between two samples taken in the next years exceeds 6 mm;

- papule more than 12 mm, although after BCG vaccination more than 4 years have passed;

- the diameter of the infiltration exceeds 17 mm.

Rules of conduct for

In order for the result obtained after 72 hours to be reliable, it is important to observe certain conditions. Only in this case, information about the size of the Mantoux should be useful. So, many from childhood remember that the injection site can not be wetted. But now the medical staff says that in contact with water there is nothing terrible. The main thing - do not rub and scratch the site of the injection, do not stick it with adhesive plaster, do not smear with peroxide, iodine or zelenka. If it gets wet, pat it with a soft cloth.


There are a number of situations in which it is not advisable to make a tuberculin test. These include the following:

- exacerbation of allergic reactions;

- infectious diseases;

- chronic diseases in the period of their acute course( in such situations the sample is made a month after remission);

- skin problems in the place where the injection is planned;

- epileptic seizures;

- quarantine for any childhood infectious diseases.

For example, if a child has an allergy or is sick, then there is no point in assessing the size of Mantoux. The normal result will be only in a healthy baby.

Possible problems

Of course, most parents are concerned about the interpretation of the results of the tuberculin test, but sometimes there are related questions. Sometimes it becomes necessary to re-inject. So, it happens in case of illness, which occurred after the introduction of tuberculin. If the moment is missed, the repeated test is carried out after a year, but if necessary, this interval can be reduced to six months.

Another problem is the non-compliance with the rules of drug administration. There is no sense in finding out what size Mantoux should be if tuberculin was injected not intracutaneously, but deeper. A sign of improper administration is the blood that appeared at the injection site.