What is considered more harmful for a child - X-ray or Mantoux

What it is?

The Mantoux test or tuberculin test is a specific diagnostic method that allows you to detect the fact of infection with the bacteria that cause tuberculosis (Mycobacterium tuberculosis, Koch bacillus).
The essence of this test is the intradermal injection of a tuberculin solution. In this case, the body, which has previously encountered tuberculosis bacteria, responds to the Mantoux test with a pronounced allergic reaction - the formation of an infiltration zone, thickening of the skin (induration).

Tuberculin itself is a combination of extracts obtained from the mycobacteria M. tuberculosis, M. bovis and M. avium. Essentially, these are antigens to which the human body's antibodies react.

Are we all sick?..

Thus, adults are considered infected by default, and doctors can only monitor the condition of their lungs in order to notice the development of the disease in time. By the way, representatives of many professions diligently avoid FLG, arguing that they are afraid of unnecessary radiation exposure. And their undetected disease proceeds hidden in the initial stages - this is how those who were previously healthy become infected.

According to the stories of phthisiologists, among the visitors to the city tuberculosis dispensary there are many wealthy, prosperous people - despite popular belief, mycobacterium tuberculosis, peacefully dormant in the lungs, “goes on the offensive” not only due to poor nutrition or living in dark, damp rooms (although these factors are of primary importance meaning). The risk is also increased by a banal decrease in immunity, which may be caused by another chronic disease or, for example, by surgery.

Why is Mantoux test done?

The tuberculin test is used as a means of mass screening of children aged 122 months to 18 years for tuberculosis. The test is easy and cheap to perform, and the results are easy to interpret. In children, the Mantoux test may be used if symptoms suggestive of tuberculosis infection are present.

This diagnostic test only shows the presence of antibodies to mycobacteria, that is, the fact of prior contact or infection. It does not make it possible to assess the activity of the tuberculosis process in the body or the degree of protection against the disease obtained after administration of the tuberculosis vaccine (BCG).

Technique for performing the Mantoux test

The Mantoux test is performed by injecting 2 units of tuberculin (TE) into the skin on the inner surface of the forearm. The injection is carried out with a special tuberculin syringe with the needle cut upward.

The tuberculin test is an intradermal injection. If performed correctly, it should cause the formation of a pale raised skin (blister) 6 to 10 mm in diameter immediately after the procedure.

At the same time, since tuberculin is injected directly into the skin, the Mantoux test can be exposed to contact with water - it is not able to penetrate into the skin and interact with tuberculin. A really important limitation is to minimize mechanical stress, which can affect the size of the induration area. In other words, the sample site should not be scratched or even touched again.

Diaskintest for tuberculosis

Diaskintest is one of the newest tests, which consists of subcutaneous injection of protein antigens of mycobacteria for further assessment of the result of contact of the human body with the causative agent of the disease. The test is considered positive in the presence of compactions and hyperemia.

The test accuracy is 95%. This is a good replacement for the tuberculin reaction, since Diaskintest practically does not cause complications.

The composition of the drug for administration includes:

• protein extract of mycobacteria;
• phenol;
• sodium chloride;
• sodium phosphate;
• sorbents;
• water for injections.

This test does not require any special preparation. The product can be injected into both hands, in the area of ​​the middle third of the forearm. Phthisiatricians recommend performing Diaskintest on the limb that is less active. This will significantly reduce the risk of mechanical damage around the injection site. The doctor also warns parents that this area should not be combed or various creams and ointments applied to it. These actions can lead to the development of incorrect reactions and possible complications.

The drug is administered using a special tuberculin syringe, which has a thin needle. The test can be performed annually on children aged 7 to 16 years.

You should also adhere to the following rules:

• if there is a negative reaction, re-use of Diaskintest is possible no earlier than after 3 months;
• after the introduction of vaccinations, this sample can be used 30 days later;
• Colds, as well as other diseases with the presence of inflammatory processes, postpone the use of the test for a month.

When observing a child in a tuberculosis clinic, control tests must be carried out every 3-6 months. This is necessary to assess the dynamics of treatment and adjust the course of using medications.

The result of Diaskintest is determined by an experienced doctor three days after the injection.

This diagnostic method may have the following reactions:

1. Negative. This result is considered normal. In this case, the only visible signs are a needle mark or slight hyperemia, the size of which does not exceed 1 mm, or a colorless papule less than 6 mm in diameter.
2. Doubtful. In this case, there is redness on the skin around the injection site without any compaction. This result is a reason to refer the child to a tuberculosis clinic for additional diagnostic methods.
3. Positive. In this case, a large papule is observed, indicating contact of the child’s body with mycobacterium tuberculosis. After receiving this result, you should immediately consult with a phthisiatrician who can choose the most effective course of therapy aimed at eliminating the disease and preventing complications.

The test has certain contraindications, in the presence of which the doctor may recommend other methods of examining the body for the presence of mycobacteria.

These include:

• acute infectious diseases;
• chronic pathologies in the acute stage;
• skin diseases;
• allergy to the components of the drug.

Before performing Diaskintest, you should consult an experienced doctor about the advisability of using this diagnostic method. This will help make the child’s anti-tuberculosis examination comfortable and safe for his health.

Sample results

The Mantoux test reaction is assessed 48–72 hours after injection. The test criterion is the diameter of the skin seal that appears. In this case, erythema (the area of ​​redness of the skin) is not taken into account. The diameter of the compacted area should be measured across the forearm, perpendicular to the axis of the arm (Fig. 1).

Figure 1. Correct measurement of the reaction during the Mantoux test. Source: MedPortal

The reaction to the Mantoux test, depending on the diameter of the induration, is:

• Negative - 0-1 mm or complete absence of reaction.
• Doubtful - 2-4 mm or the presence of hyperemia of any size without induration.
• Positive - more than 5 mm.

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Positive reactions are divided into subtypes:

• weakly positive - 5-9 mm;
• medium intensity - 10-14 mm;
• pronounced - 15-16 mm;
• hyperergic (excessively expressed) - more than 17 mm in children and 21 mm in adults.

Photo: a4ashishmishra.gmail.com / Depositphotos
Also, a hyperergic reaction, regardless of the size of the skin induration, is indicated by the formation of suppuration and areas of necrosis, damage to nearby lymphatic vessels, nodes, etc.

Induration up to 5 mm may also indicate infection with Mycobacterium tuberculosis in the following cases:

• Recent contact with a person with tuberculosis.
• Previously obtained chest x-ray results indicating previous tuberculosis.
• Underwent surgery for organ transplantation.
• HIV infection and AIDS, other immunodeficiency conditions, for example, long-term therapy with corticosteroids.

Diaskintest

Diaskintest was introduced quite recently, in 2009. This is a completely new drug for diagnosing tuberculosis, which has become a better alternative to Mantoux.

Diaskintest contains a tuberculosis recombinant allergen, consisting of two interconnected antigens. They make it possible to determine a positive reaction result in the true presence of tuberculosis, and this can be called a real breakthrough in medicine.

Diaskintest is carried out in the same way as the Mantoux test - in a sitting position, 0.1 milliliter of the drug is injected under the child’s skin, after which the result must be assessed after three days

At the same time, according to Dr. Komarovsky, it does not matter at all whether the Mantoux test was recently performed or not, the main thing is to do the Diaskintest on the other hand

Credibility

The results of the Diaskintest test are amazing - like x-rays and other types of diagnostics, its effectiveness is close to 100%. This means that in the vast majority of cases the diagnosis shows the correct answer. The effectiveness of this drug was assessed at three clinical sites, comparing it with pure tuberculin, measuring the sensitivity and specificity of the drug. To do this, tests had to be done on adults and children with tuberculosis, as well as on those who do not have it. After this, reliability was revealed in the range from 100 to 90%. This is already a very good conclusion, in comparison with the Mantoux test, which guarantees a maximum of 70% efficiency in detecting tuberculosis in children.

Sample danger

As with Mantoux, there is no risk of contracting tuberculosis from Diaskintest, because the drug was developed in a special way so as not to cause any harm to the patient. However, there is a small list of side effects that may occur as a result of the test. These include: weakness throughout the body, loss of appetite, slight fluctuations in temperature, headache, fatigue, and the appearance of hyperemia.

But these symptoms cannot be classified as specific, since they can appear if you have recently taken any pills. Therefore, there is no danger from this procedure for either adults or children.

Indications for testing

This test should be done for the purpose of diagnosing tuberculosis, assessing the activity of internal processes, and also identifying patients whose risk of developing tuberculosis processes is especially high.

The drug is used only as prescribed by a phthisiatrician, as well as under his direct control and observation. It is recommended to be administered to patients who have been referred to a hospital without additional investigations (in the form of x-rays or tests), as well as to people who are at risk for this disease. Very often Diaskintest is carried out in combination with x-rays and other diagnostic measures.

How results are assessed

Analysis of the results should be done after 72 hours, as in the case of vaccination. Many people are afraid of distorted results if they have recently taken antihistamine tablets with a child. We hasten to reassure you that neither antihistamine tablets nor any other tablets can affect the assessment of the test.

You need to measure with the same transparent ruler, and the transverse, relative to the forearm, size. A reaction is considered negative if the mark does not appear at all or does not exceed 2 millimeters. A moderately expressed result is from 5 to 9 millimeters, and a pronounced result is from 9 to 14. With more extensive irritation, we can conclude that the person is infected. If the reaction turns out to be positive, this is not yet a reason to panic; in such cases, the doctor may advise you to take the pills and do a repeat test. Usually Pyrazinamide, Chophytol, vitamin B and other similar tablets are prescribed.

As you can see, Diaskintest, in all its characteristics, is very similar to the mantoux test, however, it is considered a more advanced alternative due to its high accuracy. That is why, if you have a choice, it is better to give preference to Diaskintest, and only then carry out x-rays and other procedures.

Disadvantages of the Mantoux test

It is believed that after receiving the BCG vaccine, the Mantoux test loses its diagnostic value, since it can indicate not only a probable infection with mycobacteria, but also sensitization from vaccination. At the same time, most children have controversial, unclear test results.

One of the most important disadvantages of the Mantoux test is the high risk of obtaining false positive and false negative results. The human factor also plays an important role when measuring the reaction to the test.

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False positive result

Some people test positive for the Mantoux test even if they are not infected with M. tuberculosis. At the same time, induration, as a rule, does not have clear boundaries, its diameter is 5-7 mm and it disappears after 1.5-2 weeks, and not 5-7 days, as expected.

Reasons for these false positive reactions may include:

• Recent introduction of BCG vaccination. To obtain true data, the test should be carried out no earlier than 12 months after vaccination.
• Infection with mycobacteria other than M. tuberculosis.
• Incorrect measurement or interpretation of response.

False negative result

There are situations when the Mantoux test shows a negative result in patients infected with M. tuberculosis. A false negative reaction can be caused by:

• Tuberculosis infection suffered during the last 8-10 weeks.
• Age less than 6 months.
• Recent vaccination against measles and smallpox.
• Incorrect measurement or interpretation of response.

What diagnostic methods exist

How can you safely examine a child for pulmonary tuberculosis without performing a tuberculin test? Many parents are puzzled by this question today, since no one likes to take their child to a tuberculosis clinic when dubious results are revealed. Currently, the most common methods are the introduction of Tuberculin and fluorography, but a lot of controversial information and negative reviews have appeared around these diagnostic methods. Phthisiatricians assure that there are other effective methods that will help identify reliable results, and at the same time are guaranteed not to cause harm to the child’s health.

Since a law has been adopted according to which preventive examinations of children attending children's educational institutions are mandatory, it is impossible to refuse the diagnosis of tuberculosis. Mass vaccination is mandatory and is carried out once a year. If a child has not been diagnosed and does not have the appropriate certificate, he will not be allowed into any educational institution.

According to statistics, many parents are afraid to make Mantoux for certain reasons. This is due to the fact that the test often gives a false positive result. In addition, it is believed that administering Tuberculin, even in a minimal dosage, is unsafe for health. The legislation has established that parents have the right to refuse a tuberculin test, but it will have to be replaced by another method.

As an alternative use:

1. Blood analysis. In practice, this diagnostic method is rare, more often if the patient has a positive reaction. Taking blood to detect mycobacteria in the body is called ELISA (enzyme-linked immunosorbent assay) or PCR (polymerase chain reaction). This diagnostic method does not give a false positive reaction and is considered the best alternative to Tuberculin.
2. X-ray. Most doctors do not recommend taking x-rays instead of Mantoux, since ionizing radiation negatively affects the baby's health. Radiography is necessary if a positive result for the presence of Koch bacilli is revealed during third-party diagnostic methods. In such a situation, an x-ray is necessary, as it will help identify the exact clinical picture and find foci of pathology.
3. Diaskintest. Subcutaneous injection of recombined tuberculosis allergens.
4. Quantiferon test. Its action is very similar to Diaskintest, only the composition is not administered subcutaneously, the blood is mixed with other reagents in a test tube.
5. Fluorography. This method of identifying pathogenic mycobacteria is “classical”; it is carried out only after 14 years.

Each diagnostic method has advantages and disadvantages, so it is recommended to choose a method together with a doctor who will tell you what is more relevant in a particular case.

Alternatives to the Mantoux test

If a false-positive or false-negative Mantoux test result is suspected and in some other cases, it may be necessary to use alternative methods for the early diagnosis of tuberculosis. The most common options are:

• Diaskintest. Like the Mantoux test, it is an intradermal test in which a reaction occurs exclusively to M. tuberculosis antigens. Less common pathogens of tuberculosis and opportunistic mycobacteria do not cause the formation of induration.
• T-SPOT. It is based on the detection in venous blood of specific immune cells (T-lymphocytes) synthesized in response to infection with M. tuberculosis.
• Quantiferon (QuantiFERON-TB Gold). The principle is similar to T-SPOT, but the test evaluates not the number of T-lymphocytes, but the level of interferon gamma.

Advantages and disadvantages of radiography

X-ray is an accurate method for diagnosing pulmonary tuberculosis. After all, using this method, the doctor can assess the condition of the lung tissues and the degree of their damage. The advantage of this study is that the X-ray image distinguishes tuberculosis from cancer, pneumonia, etc.

X-ray allows you to accurately understand the localization of pathological foci. Also, a positive factor in performing radiography is the ability to determine the type of damage to the lung tissue. That is, tuberculosis is focal, infiltrative, cavernous, disseminated in nature.

Also, this study has no contraindications. Even pregnant women in the first trimester can undergo an x-ray if tuberculosis is suspected. The woman’s stomach is simply covered with a special vest that protects from X-ray rays.

The main disadvantage of this method is the radiation exposure that is applied to the body during the procedure. The safe radiation dose for humans is 1 mSv per year. This is just one procedure. If a person is sick with tuberculosis, then it is necessary to take x-rays quite often - about 10-20 times a year. With this load, there is even a possibility of developing cancer.

The most gentle method is digital radiography. It is considered safer due to the fact that the minimum dosage of radiation exposure during a digital study is 0.01 mSv.

Repeated Mantoux test

Typically, repeated tuberculin administration is not associated with any health risks. For example, if a person does not return for a follow-up examination within 48 to 72 hours to evaluate the results of a tuberculin skin test, it is recommended that a second test be performed as soon as possible. There are no contraindications to repeating the Mantoux test, except in cases where the previous test was associated with a severe allergic reaction.

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Tuberculin diagnostics, as a rule, are carried out annually, and its results are compared with previous ones. Sometimes this is an infection with M. tuberculosis since the last test.

The criteria by which a child can be referred for consultation to an anti-tuberculosis dispensary after a Mantoux test includes the following:

• a newly detected positive reaction (papule 5 mm or more) to a test that is not related to previous immunization against tuberculosis;
• long-lasting (4 years) reaction with an infiltrate of 12 mm or more;
• an increase in sensitivity to tuberculin in tuberculin-positive children - an increase in infiltrate by 6 mm or more;
• an increase of less than 6 mm, but with the formation of an infiltrate measuring 12 mm or more;
• hyperreaction to tuberculin (infiltrate 17 mm or more);
• vesiculonecrotic reaction and lymphangitis.

It is also worth mentioning the “Booster effect” - a significant increase in the resulting reaction with frequent (more than once every 2 weeks) testing. It is believed that this effect is due to an increase in the sensitivity of T lymphocytes to tuberculin. At the same time, the immunity of individuals infected with M. tuberculosis for a long time stops responding to tuberculin, which may result in a false negative result.

Contraindications to the Mantoux test

In some situations, the Mantoux test must be delayed or cannot be performed at all, and therefore is replaced by alternative diagnostic methods. Possible reasons for failure to perform the test include:

• Active infection in the body.
• Exacerbation of chronic pathologies.
• Presence of skin rashes or skin diseases.
• Bronchial asthma, allergic diseases.
• Quarantine in a child's educational institution.
• Receipt of vaccinations within the last month.

Is it possible to refuse Mantoux?

The Mantoux test is a voluntary diagnostic procedure that can be performed on a child only with parental consent. You can also refuse it by referring to Art. 20 of the Law on the Fundamentals of Protecting Citizens' Health.

A test is often required in schools and kindergartens before children are allowed to attend classes. If, for medical reasons or the personal beliefs of the parents, the child does not undergo tuberculin diagnostics, the educational institution must be provided with a doctor’s certificate stating that the child is healthy.

This is stated in clause 5.7 of the Sanitary and Epidemiological Rules SP 3.1.2.3114-13 “Prevention of Tuberculosis”, approved. Resolution of the Chief State Sanitary Doctor of the Russian Federation dated October 22, 2013 No. 60.

Sources

1. Lewinsohn et al., Official American Thoracic Society/Infectious Diseases Society of America/CDC Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Childrenexternal icon, Clinical Infectious Diseases, 2021, Pages e1–e33.
2. Kim Y, Dawes-Higgs E, Zagarella S. Foreign body reaction involving a Mantoux test site. Australas J Dermatol. 2005; 46:169–71
3. Tuberculin diagnostics // Great Medical Encyclopedia: in 30 volumes / chapter. ed. B.V. Petrovsky. — 3rd ed. - M.: Soviet Encyclopedia, 1985. - T. 25: Tenius - Carbon dioxide. — 544 p.
4. Borodulina E. A. Issues of tuberculin diagnostics in children in modern conditions // Issues of modern pediatrics. - 2010. - T. 9, No. 1 - P. 70−74.