In the fight against the mass vaccination campaign, many at the same time refuse Mantoux tests. But this small injection has nothing to do with vaccination. In this way, doctors simply check how the immune system responds to the introduction of tuberculin. Normally, a small inflammatory process should develop. To understand the reaction of the body, you need to know what the size of the Mantoux should be. The norm is set depending on the age of the baby and the timing of the introduction of BCG vaccination.
To and when do Mantoux
Basically, this method checks the health status 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 vaccine was not violated for some reason, then the first Mantoux test is done in one year.
If the baby was not vaccinated in the hospital or in the first month of life, then a tuberculin test is done before BCG to exclude the disease. Many are interested in what should be the size of the Mantoux in a child without this vaccination. If the baby's immunity is not familiar with tuberculosis, then there should not be any reaction. Usually at the injection site in a healthy and unvaccinated baby, redness or thickening does not form.
Risk group
Many parents refuse tuberculin tests, explaining 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 and your child visit public places, whether it’s a kindergarten, developing clubs, schools, theaters or exhibitions, go on a visit and use the transport other people drive, then you endanger your child.
Being in society, you run the risk of meeting a patient with tuberculosis, who, perhaps, himself does not know about his illness. Please note: in the lungs, any adult has mycobacteria of this disease. As long as immunity is able to restrain 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 take a TB test on time and know what the size of the Mantoux should be.
Drug reaction
Everyone knows that the result of a tuberculin test is evaluated 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 reddish color. If you press it down with a transparent ruler, you will see how it turns pale. It is this solid site that needs to be investigated, because it shows the size of the Mantoux. The rate of this reaction depends on when the child was given BCG.
Many do not know why they are injecting tuberculin. This study allows you to determine if there
are Koch sticks in the body
. It can also show the period of activation of the infection and confirm the diagnosis of tuberculosis. In addition, with its help it is possible to identify children who have completely no immunity to this disease.
Established standards
In our country, it is customary to do BCG in the hospital, and the first injection of tuberculin - per year. Previously, it makes no sense, because the result may be distorted. To understand if your child has problems, you need to figure out what the size of the Mantoux should be. A sample is considered negative if, after 72 hours, only the injection site is visible, and there is no infiltrate at all. With a papule with a diameter of 2-4 mm or redness of any size, the result is considered doubtful. If the infiltrate is in the range of 5-17 mm, then this is considered a positive reaction. At the same time, it is divided into medium - five to nine, intensive - ten to fourteen, and pronounced - in excess of fifteen millimeters.
If the Mantoux sizes in children exceed 17 mm or bubbles appear in the injection area, a necrotic zone or lymph nodes increase, then this is called a hyperergic reaction, for adults this limit is 21 mm.
Evaluation Rules
For an adequate understanding of the situation, it is important to know that a negative test occurs only in the absence of immunity to tuberculosis. If the child has BCG, and there is no reaction to tuberculin, then the vaccine does not work, it is advisable to have a booster shot. If the baby is first given a Mantoux reaction, its size can be quite large. If no more than two years have passed after the vaccination, it should be positive - this indicates an adequate reaction of the body to BCG. Note that in this case, the baby must have a scar at the injection site. If it is not, and Mantoux is positive, then this indicates infection of the body.
Two years after vaccination, the size of the infiltrate should decrease. As a rule, he disappears completely by the age of seven. Just at this time, they re-vaccinate BCG, with it help strengthen the immune system. The reduction in the size of the “button” indicates that, most likely, infection occurred.
Sample Turn
When figuring out what the Mantoux size should be, it is important not only what the ruler will show, but also how this indicator changes from year to year. So, the following situations are called a turn of a tuberculin test:
- the first appearance of a positive Mantoux, provided that the previous results were less than 5 mm;
- the size difference between two samples made in neighboring years exceeds 6 mm;
- papule more than 12 mm, although more than 4 years have passed after BCG vaccination;
- the diameter of the infiltrate exceeds 17 mm.
Rules of behavior
In order for the result obtained after 72 hours to be reliable, it is important to comply with certain conditions. Only in this case, information about how large Mantoux should be will be useful. So, many from childhood remember that the injection site can not be wet. But at present, the medical staff says that there is nothing to worry about in contact with water. The main thing is not to rub or scratch the injection site, not to glue it with adhesive tape, in any case not to smear with peroxide, iodine or brilliant green. If it gets wet, pat it with a soft cloth.
Contraindications
There are a number of situations in which it is not practical to make a tuberculin test. These include the following:
- exacerbation of allergic reactions;
- infectious diseases;
- chronic diseases during their acute course (in such situations, a test is done 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 is allergic or sick, then it makes no sense to estimate the size of the Mantoux. A healthy result will only be in a healthy baby.
Possible problems
Of course, most often parents are concerned about the interpretation of the results of the tuberculin test, but sometimes related questions arise. Sometimes there is a need for a second injection. So, this happens in the case of a disease that has occurred after the introduction of tuberculin. If the moment is missed, then a second 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 administration of the drug. It makes no sense to find out what size Mantoux should be if tuberculin was injected not deeper than the skin. A sign of improper administration is blood that appears at the injection site.