When we were given a tuberculin test (also known as the Mantoux test) at school, they did not forget to remind us every time: under no circumstances should the injection site be wet. Have we been deceived all this time?

There are two types of tuberculin diagnostics: the Pirquet test and the more well-known and modern Mantoux reaction. Both are aimed at testing the resistance of immunity to tuberculosis pathogens, but the test methods are different. Pirquet's test involves scarification - making a small scratch on the skin through which tuberculin is introduced into the body. When performing the Mantoux reaction, the solution is injected under the skin, and then please don't get it wet this place.

Several myths are associated with the Mantoux reaction. For example, from the moment of tuberculin administration until the size of the “button” is measured, one should supposedly not eat sweets or take antiallergic drugs. But, of course, the most common is not allowing water to enter the area of the skin where the injection was given.

Apparently, this is due to the fact that the Pirquet test, a more outdated technology, involved scratching the skin and liquid could get into the scratch. Therefore, patients were asked not to wet this area. How notes Dick Menzies, a researcher at McGill University Medical Center in Canada, you can wet Mantu 15 minutes after the injection. You need to be careful after you have washed your hands or taken a shower: the area of skin on which the test was carried out cannot be rubbed, so you should carefully blot it with a napkin or soft towel.

Foreign colleagues are also supported by Russian specialists. In 2018, the chief phthisiatrician (that is, a specialist in the diagnosis and treatment of tuberculosis) of the Russian Ministry of Health statedthat contact with water on the skin does not affect the results of the study. Anna Vasilyeva said: “You can get it wet, then just get wet and that’s it. <…> With the Mantoux test, everything is not so strict - you just can’t irritate the skin.”