Evaluation of tuberculin skin test results of one year

Abstract

Objective: We aimed to determine reasons for Tuberculin Skin Test (TST) application, positive TST frequency and the factors influencing positivity in children in the Uludag University Medical Faculty Pediatric Infectious Disease Outpatient Clinic.Materials and Methods: In the Outpatient Clinic, TST was applied to 503 children between January 1st-December 31th. The reasons for the TST application, TST positivity and factors influencing positivity were evaluated. 5 TU of Purified Protein Derivative (PPD) was given, and the test was evaluated after 72 hours by measuring the diameter of enduration. Ages, genders, BCG scarring, contact with tuberculosis disease and diagnosis were recorded.Results: Of the patients, 52.9% were boys with a mean age 7.71 +/- 4.7 years (1 month-18 years). Diagnoses of patients were, frequent infection in 30.8%, prolonged cough in 24.3%, asthma/bronchial hyperreactivity (BHR) in 11.1%, recurrent pneumonia in 8.2%, close contact with tuberculosis in 6.5%, peripheral lymphadenopathy in 5.4%, tuberculosis disease in 2.4%, immunodeficiency in 2.6%, bronchiectasis in 1.6%. Most frequent cases of TST positive patients (73.5%) were in the tuberculosis close contact group. TST positivity was 55.7% in the prolonged cough group, 30.9% in the frequent infection group, 33.9% in the asthma/BHR group, 19.5% in the recurrent pneumonia group, 29.6% in the lymphadenopathy group, 38.4% in the immunodeficiency group and 50% in the bronchiectasis group. 40.7% of patients had TST>15 mm, 26.4% TST=10-14 mm and 30.7% TST<10mm in induration. TST positivity rate increased with BCG scarring number (p<0.001) and older age (p<0.001). Of the patients 91.5% had BCG scarring, while 75.1% had 1 scarring, 16.4% had 2 scarrings.Chest PA graphy of all patients with positive TST were evaluated and 92.4% were normal, 3.1 % revealed pneumonia, 1.3% atelectasis and 1.2% revealed hiler lymphadenopathy. Of the patients evaluated with Thoracic CT (7.9%), 40% were normal, 22.5% revealed pneumonia, 22.5% bronchiectasis and 15% hilar/subcarinal lymphadenopathy. 40% of patients were given prophylaxis, 3.3% were given antituberculosis treatment.Conclusion: As the study group consisted of children of different ages with risk factors for tuberculosis disease from different sociocultural environments, more studies evaluating TST results are needed.