Common alternative diagnoses among a pediatric hospital-based cohort evaluated for tuberculosis in Karachi, Pakistan: The need for facilitated referral in tuberculosis clinics

Background: Children evaluated for tuberculosis (TB) are often diagnosed with miscellaneous conditions that mimic TB. Knowledge of differentials informs policy on service provision through liaison with referral centers offering definitive diagnosis and treatment for common alternative disorders. Methods: We reviewed medical records of children who were offered diagnostic testing for TB (culture or Xpert MTB/RIF) at a tertiary care hospital in Karachi, Pakistan to identify common alternative diagnoses among children who are evaluated for TB. Results: From January 2014 to December 2015, of 126 culture or Xpert MTB/RIF negative children presenting with chronic symptoms, 31 were diagnosed and treated for TB based on clinical criteria (5 of 48 children with pulmonary and 26 of 78 with extrapulmonary presentations; 10.4% and 33.3%, respectively). Among remaining 95 patients, common alternative diagnoses to pulmonary TB (n = 43) were bacterial pneumonia or empyema (60.5%, n = 25) and underlying bronchiectasis (20.9%, n = 9). Among 52 extrapulmonary presentations, the most common alternative diagnoses were lymphoproliferative disorders (n = 11, 21.1%), bacterial infections (n = 11, 21.1%), and autoimmune disorders (n = 9, 17.3%). Of note, five children were diagnosed with underlying primary immunodeficiencies (9.6%). Children with alternative disorders were treated for TB in 25 of 95 cases (26.3%). Although 77.8% (n = 98) children were followed up at the facility, 15.9% (n = 20) were lost to follow-up. Conclusions: Pediatric TB mimics many disorders that primary level centers are not equipped to diagnose or manage, leading to suboptimal outcomes. Knowledge of common alternative diagnoses is essential to inform facilitated referral for common mimicking disorders in children.