Diagnosis and treatment of extrapulmonary tuberculosis

Diagnosing extrapulmonary tuberculosis (E-TB) remains a challenge because clinical samples obtained from sites that are not easily accessible are sometimes paucibacillary, decreasing the sensitivity of diagnostic tests. Adenosine deaminase (ADA) is widely used for adjunct diagnosis of E-TB with extrasanguinous fluid. However, ADA is not a specific marker for E-TB, so a more specific test is urgently needed for the confirmation of E-TB. Recently, an IFN-gamma releasing assay using peripheral blood mononuclear cells and extrasanguinous fluid mononuclear cells, and the newly-developed Xpert MTB/RFP have shown promising results for the rapid diagnosis of E-TB. Although the regimen of antituberculous medication for E-TB is similar to that for pulmonary tuberculosis, the treatment of E-TB is occasionally complicated due to a paradoxical response during antituberculous therapy and after the completion of antituberculous therapy, especially in tuberculous lymphadenopathy. The proposed algorithm for the management of paradoxical response in tuberculous lymphadenopathy is presented, and the treatment for E-TB in various sites is briefly reviewed.