A rare cutaneous tuberculosis form, erythema induratum of Bazin: 6 years' experience.

Introduction Erythema induratum of Bazin (EIB) is a rare tuberculid form characterized by hypersensitivity to Mycobacterium tuberculosis antigens. There are a few case series related to EIB in the literature. We evaluated the demographic, clinical, treatment, and follow-up characteristics of patients diagnosed with EIB. Methods Demographic, clinical, histopathologic, and imaging findings as well as treatment and follow-up properties were evaluated in 22 patients retrospectively diagnosed with EIB between January 2013 and December 2018. Results Of the 22 patients,90.9% were female and 9.1% were male. The mean age was 57.2 ± 12.9 years. Ten of the patients had a history of contact with tuberculosis, and one had a history of active pulmonary tuberculosis. The purified protein derivate (PPD) test average was 18.1 mm. The lesions were located in the lower extremity in all patients and in the upper extremity in 31.8% of patients. Histopathologically, 22.7% had vasculitis, 27.3% were treated with four tuberculosis drugs, and 72.7% were followed without tuberculosis treatment. Treatment was continued for two patients, and 75.0% of the patients treated with a four-drug regimen recovered. Relapse was observed in one of the patients after 36 months. The recovery rate was found to be 87.5% in patients that did not receive tuberculosis treatment, and there were no relapses in the follow-up. Conclusions EIB's etiopathogenesis is unknown. In total, 75.0% of the patients receiving tuberculosis treatment and 87.5% of the patients without tuberculosis treatment recovered in our study. The role of tuberculous therapy in the management of EIB is controversial. The selection of appropriate treatment for EIB continues to be an area of debate, and further studies are needed.