Erythema induratum in a patient with active tuberculosis of the axillary lymph node: IFN-gamma release of specific T cells

The pathogenesis of erythema induratum (EI) and its relationship to tuberculosis (TB) are still poorly understood, and while there is no doubt that for some of EI such a relationship exists, there are good reasons to doubt it in others. The tuberculous etiology of EI is largely circumstantial and not always convincing. Active TB is found only rarely in EI patients [1]. We herein report a case of EI in which concurrent active TB of the [...]