Erythema Induratum Associated with Tuberculous Lymphadenitis: Analysis of a Case Using Polymerase Chain Reactions with Different Primer Pairs to Differentiate Bacille Calmette‐Guérin (BCG) from Virulent Strains ofMycobacterium tuberculosisComplex

Abstract

We retrospectively analyzed a bacille Calmette-Guérin (BCG) vaccinated female patient who developed erythema induratum in association with tuberculous lymphadenitis. The polymerase chain reaction (PCR) with two pairs of primers was performed. Only one pair was able to detect the myocobacterial DNA from the paraffin-embedded specimen of the erythema induratum (EI) lesion. However, both pairs showed positive results with the tuberculous lymphadenitis specimen. Sequence analysis of the PCR products excluded the possibility of BCG as the potential pathogen. Both lesions responded favorably to antituberculous therapy. Our study attests to the tuberculous nature of EI and demonstrates that BCG vaccination per se does not induce the lesion or interfere with the PCR result. Finally, using at least two pairs of primers targeting different genomic segments and possessing species-identification capability may raise the detection rates and solve some controversies about the nature of tuberculids.

Disseminated Cutaneous Bacille Calmette‐Guérin Infection Identified by Polymerase Chain Reaction in a Patient with X‐linked Severe Combined Immunodeficiency

“…As reported by Magdalena et al, this method has a sensitivity and specificity of 100% (5). We used it previously to differentiate BCG from other strains (17). Further alignment confirmed that the source of infection was the BCG vaccine (Tokyo 172) the patient had received at 3 days of age.…”

Polymerase chain reaction based detection ofMycobacterium tuberculosisin tissues showing granulomatous inflammation without demonstrable acid‐fast bacilli

“…The availability of the 16S rRNA gene allowed the pan‐ Mycobacteria primers (KY75/KY18) to amplify efficiently from most Mycobaterium species with high sensitivity and specificity 13 . We included two pairs of primers in our study to increase the sensitivity of detection as Wang et al 27 . recommended.…”