What is Mantoux test
The principle of Mantoux test is the intradermal introduction to the human body small doses of tuberculin – specific antigen derived from Mycobacterium tuberculosis, and the subsequent observation of the local response. The introduction of the drug reacting T-lymphocytes are blood cells responsible for anti-TB immunity, so the injection is redness and swelling.
When the test is considered positive
The intensity of the inflammatory response depends on the content and activity of bacteria in the body. If a person had a chance to "meet" with the tubercle Bacillus, the sample result will be "positive". In this case, the inflammation predominates over the natural reaction caused by the introduction of tuberculin. Evaluation of Mantoux test is the measurement of the papules – seal, which is detectable under the skin. The measurement is performed 72 hours after placing samples in the transverse direction to the axis of the hands, a transparent ruler and good lighting.
What do the results
The result will be positive if the diameter of the seal is 5 mm When the size of the papules 5-9 mm reaction is estimated as weakly positive, 10-14 mm – medium intensity, 15-16 mm – severe. Giperergicakie is considered an inflammatory reaction at the size of 17 mm papules in children and 21 mm in adults, and in the presence of vesiculo necrotic entities, regardless of the diameter of the seal. An important feature of tuberculosis infection is the presence of pigmentation (brown staining) in the site of injection within 1-2 weeks after the Mantoux test. In contrast to the usual pink seal, post-infectious papule has a clear contours, and remained about 2 weeks.
A positive Mantoux test is not a reason to panic!
The Mantoux test is only an indicative test. For TB diagnosis and appointment specific treatment takes into account a number of important factors. Therefore, a positive result is the only reason for consulting the doctor-phthisiatrician, who will prescribe microbiological examination of the sputum and chest x-ray. If infection is not confirmed, the reaction may be the result of Allergy to tuberculin. Holding the sample within one month after immunizations, diseases or aggravation of Allergy may be the cause of false positive reactions.