A Case of Erythema Induratum of Bazin Necessitating Protracted Treatment for Complete Remission: Are We in Need of Disease-Specific Therapy Guidelines?

Erythema induratum of Bazin (EIB) is a rare subcutaneous granulomatous disease that is considered to represent a form of tuberculin hypersensitivity. We present the case of a 74-year-old Bacillus Calmette-Guerin (BCG)-vaccinated female patient, who presented to our dermatology clinic with painful, erythematous purple nodules on the lower extremities. Clinical examination, histopathological analysis, a positive tuberculin skin test (TST) and interferon-gamma release assay (IGRA) supported the diagnosis of EIB. A standard six-month anti-tubercular therapy (ATT) led to improvement of the clinical presentation. However, after discontinuation of ATT, the clinical symptoms and sings relapsed and ATT had to be extended for a total of 10 months to achieve complete remission without relapse for 12 months. Given the lack of established treatment guidelines for the management of EIB, this case underscores the need for prolonged ATT for the effective management of this condition, which is guided by the relevant clinical picture and sometimes goes beyond standardized anti-tubercular treatment protocols.