Role of GeneXpertMTB/RIF in the diagnosis of cutaneous tuberculosis.

BACKGROUND: cutaneous involevemtn is an important extrapulmonary manifestation of tuberculosis. It is a paucibacillary condition and has diverse clinical presentations. Sufficient data is not available regarding role of GeneXpertMTB/RIF in cutanoues tuberculosis.

METHODS: in this study, BacT/Alert3D and response to antitubercular therapy were taken as gold standard and performance of GeneXpertMTB/RIF was evaluated against it in clinically and histopathologically suspected cases of cutaneous tuberculosis.

RESULTS: forty seven patients were included in the study of which commonest presentation was scrofuloderma (42.6%) followed by lupus vulgaris (40.4%). Granulomatous inflammation on histopathology was seen in 75.5% patients on skin biopsy. Sic patients had extracutaneous focus of tuberculosis. In 14 (29.79%), culture of skin biopsy was positive for M. tuberculosis and all showed complete response to ATT in 6 months. GeneXpertMTB/RIF detected M. tuberculsois in 4 samples.

CONCLUSION: GeneXpertMTB/RIF is not a reliable tool for diagnosis of cutaneous tuberculosis. Clinic-histopathological correlation along with response to ATT is needed for confirmation of diagnosis of cutaneous tuberculosis.