Clinical observation and antituberculous treatment of erythema induratum (Bazin's disease)

Background: Erythema induratum was first described by Bazin in association with tuberculosis. However, the tuberculous cause of this entity has been questioned by several authors and gradually, the concept of nontuberculous nodular vasculitis has been accepted. Objective: The purpose of this study is to document the clinicopathologic features and erythema induratum. Methods: We investigated clinical and histopathological findings of 31 patients with erythema induratum who showed positive tuberculin hypersensitivity reaction or had active associated tuberculosis. Results: The ages of the 31 patients (M7:F24) ranged from 13 to 66 years (mean 37.1 years). All patients displayed recurrent crops of tender, painful, violaceous nodules or plaques. Most lesions were present on the legs, but they also occurred on the thighs, feet, buttocks, and forearms. The skin lesions evolved for several weeks and healed with scarring and residual pigmentation. Histological examination revealed lobular or septolobular panniculitis with varying combinations of granulomatous inflammation, primary vasculitis and necrosis in most biopsies. Twenty-two patients were treated with isoniazid alone and the remaining 9 patients received combination antituberculous treatment. Relapses were encountered in 4 patients who received isoniazid alone or stopped the medication against medical advice. Conclusion: A diagnosis of erythema induratum should be rendered in the presence of relevant clinicopathologic features, strong positive Mantoux test reaction, and good therapeutic response to antituberculous treatment. A full course of combination antituberculous therapy is indicated to achieve a cure of the skin lesions of erythema induratum.