What symptom can tuberculosis PPD skin test appear

summary

With the increase of the incidence rate of tuberculosis, the PPD test has been applied to the diagnosis of tuberculosis in recent years. However, when judging the results and clinical significance of the PPD test, the patients are not able to get reasonable explanations and guidance due to the lack of knowledge and incorrect understanding of the medical staff. Even the phenomenon of affecting the prognosis of the disease is common. In the clinical diagnosis of tuberculous diseases, it is in addition to tuberculosis examination, imaging examination, the most commonly used means of examination. Pulmonary tuberculosis PPD skin test will appear what symptoms, now talk to you.

What symptom can tuberculosis PPD skin test appear

First, in PPD test, 0.1mltb? PPD diluent (5iu) is usually injected intradermally into the flexor side of the left forearm. The diameter (mm) of skin induration is measured 48-72 hours after injection. If it is less than 5mm, it is negative; if it is 5-9mm, it is weak positive; if it is 10-19mm, it is positive; if it is more than 20mm or has local blister, death or lymphangitis, it is strong positive.

Second: infants and young children: commonly used in the selection and monitoring of BCG vaccination. If the skin test is strongly positive, it often indicates that there are active tuberculosis foci in the body. Tuberculosis examination, imaging examination, ESR and other examinations should be carried out in time to determine the diagnosis and treatment.

Third: adults: because the tuberculosis infection rate of adult residents in densely populated areas of cities and towns in China is very high, if ppd5 unit test is positive, it only means that there is tuberculosis infection, not necessarily illness; but when it is strongly positive, it often indicates that there is active tuberculosis focus. Therefore, the diagnostic value of TB? PPD test in the diagnosis of adult tuberculous diseases is limited.

matters needing attention

The first infection of tubercle bacillus within 4-8 weeks, severe malnutrition, malignant tumor, body immune deficiency diseases (congenital immunodeficiency, AIDS), immunosuppressant users, etc., individual elderly people often show negative reaction due to low body allergy function.