Erythema induratum with pulmonary tuberculosis: report of three cases.

Three cases of erythema induratum which occurred in the patients with pulmonary tuberculosis are described. The cutaneous lesions were violaceous, indurated nodules on both lower legs above the malleoli. Histologically, tuberculoid granuloma with caseation necrosis was found in one case; necrotizing vasculitis was the prominent finding in other two cases. The erythema induratum promptly responded to antituberculous therapy. We believe that, in light of these cases, the association between erythema induratum and infection with tubercle bacilli should be re-emphasized.