Application of the QuantiFERON® -TB gold test in two cases of Erythema Induratum of Bazin

Erythema induratum of Bazin is a chronic, nodular subcutaneous eruption usually occurring on the lower legs of young women. Erythema induratum of Bazin hasbeen regarded as a tuberculide, a hypersensitivity response to Mycobacterium tuberculosis. The pathogenesis of erythema induratum of Bazin associated with tuberculosis is still debatable because mycobacteria cannot be cultured from the skin lesions. QuantiFERON®-TB Gold test detects INF- γ released by T cells in response to Mycobacterium tuberculosis-specific antigens, which offers an improved diagnostic test of latent tuberculosis infection. We experienced two cases of erythema induratum of Bazin, which showed normal chest X-ray and negative TB-PCR. However the QuantiFERON -TB Gold test was positive which led us to a diagnosis of latent tuberculosis infection. Both patients were treated with anti-tuberculosis medications, which was followed by successful resolution of the skin lesions. Therefore, we report the application of the QuantiFERON®-TB Gold test for the confirmation of latent tuberculosis infection in erythema induratum of Bazin patients.