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

Int J Dermatol. 2009 Jan;48(1):27-35. doi: 10.1111/j.1365-4632.2009.03807.x.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Biopsy, Needle
  • Brazil / epidemiology
  • Cohort Studies
  • DNA, Bacterial / analysis
  • Female
  • Humans
  • Immunohistochemistry
  • Incidence
  • Male
  • Middle Aged
  • Mycobacterium Infections, Nontuberculous / diagnosis*
  • Mycobacterium Infections, Nontuberculous / epidemiology
  • Mycobacterium tuberculosis / isolation & purification*
  • Polymerase Chain Reaction / methods*
  • Risk Factors
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Sex Distribution
  • Skin Diseases, Bacterial / diagnosis*
  • Skin Diseases, Bacterial / epidemiology
  • Tuberculin Test
  • Tuberculosis, Cutaneous / diagnosis*
  • Tuberculosis, Cutaneous / epidemiology
  • Young Adult


  • DNA, Bacterial