Background: Differentiation of cutaneous tuberculosis from other infective granulomas of the skin is difficult due to paucity of the organisms in tissue biopsies. Polymerase chain reaction (PCR) is a newer technique to identify the DNA of
Mycobacterium tuberculosis
in the tissues.
Aim: We examined the utility of PCR as a tool for rapid diagnosis of cutaneous tuberculosis especially in cases negative by ZN staining and culture.
Material and Methods: Twenty five random skin biopsies from patients with various types of cutaneous tuberculosis were subjected to PCR.
Results: An overall positivity of 64% was observed, which is comparable to other series. Seventy five percent of lupus vulgaris cases, 62.2% of tuberculosis verrucosa cutis and 50% of scrofuloderma cases showed PCR positivity.
Conclusion: Though useful, the cost and the technique involved limit the use of PCR in developing countries like ours.
