Background and aims: The differential diagnosis between tuberculosis (TB) and lymphadenitis caused by nontuberculous mycobacteria (NTM) in children is often based on epidemiologic and clinical data. The aim of this study was to identify epidemiologic and clinical variables associated with TB lymphadenitis in children attending 2 TB out-patient clinics in northern Italy during a 10-year period.
Patients and methods: All children less than 16 years of age attending the study sites suspected of mycobacterial disease from 1999 through 2008 were included in the analysis. Logistic regression was used to evaluate the variables independently associated with TB lymphadenitis.
Results: From 299 children diagnosed with mycobacterial disease 121 children (40%) had a clinical diagnosis of cervical mycobacterial lymphadenitis: 38 TB (31%) and 83 NTM lymphadenitis (69%) cases. Increasing age (OR, 1.29; 95% CI, 1.02-1.69; P = 0.04), being foreign born (OR, 11.60; 95% CI, 1.37-114.20; P = 0.02), and having an abnormal chest radiograph (OR, 18.32; 95% CI, 2.37-201.68; P = 0.008) were independently associated with TB lymphadenitis. In the selected model, a 5-year-old foreign born child with cervical lymphadenitis and abnormal findings on chest radiograph has an estimated 0.90 probability of having TB disease. On the other hand, an Italy born child of the same age with cervical lymphadenitis and normal chest radiograph has a 0.04 probability of having TB.
Conclusion: Epidemiologic and clinical data are useful tools in the differential diagnosis between TB and NTM lymphadenitis when etiologic diagnosis is not available.