Polymerase chain reaction compared to other laboratory findings and to clinical evaluation in the diagnosis of cutaneous tuberculosis and atypical mycobacteria skin infection

Abstract

Background: Cutaneous tuberculosis has re-emerged in the last 15 years together with the higher incidence of pulmonary tuberculosis and multidrug resistance. The choice for a single diagnostic tool among the many available today is a challenge. Our objective was to compare polymerase chain reaction (PCR) with other exams in the diagnosis of cutaneous tuberculosis and atypical mycobacteria skin infection. Methods: PCR and a set of five different exams were performed in 32 patients (34 samples of paraffin-embedded tissue) evaluated for 3 years in a university hospital, considering the response to mycobacterial infection treatment as a positive case. Results: PCR was the most sensitive (88%) and specific (83%) exam. Culture, immunohistochemistry and acid-fast bacilli were not in agreement with clinical response to treatment. Conclusions: Although PCR is a useful tool, careful clinical exam is still the gold standard for the evaluation and treatment of cutaneous tuberculosis and mycobacteria skin infection. © Journal compilation © 2009 International Society of Dermatology.