JMIR Publications

ABSTRACT

Tuberculosis is one of the leading causes of death worldwide. Mycobacterium Tuberculosis is almost exclusively transmitted via aerosolized droplets. Immunity develops to the tuberculosis infection, but bacteria can survive intracellularly without presenting with clinical symptoms. Patients may develop a latent tuberculosis infection that can lead to reactivation at any time. A tuberculid that can cause reactivation of the tuberculosis infection is Erythema induratum of Bazin. This type of lobular panniculitis presents with granuloma formation, necrosis, and fibrosis which is particularly seen in the lower legs. Few cases of tuberculosis of the skin have been reported to date. This case report presents a 64-year-old female with a nodule on her right leg. The nodule had been noted for the past 4 weeks. The patient reported that she has had about 15 similar nodules over the past 15 years, each resolving in several weeks. An excisional biopsy of the nodule was taken and showed lobular lymphohistiocytic panniculitis with necrosis. Fite and Auramine-Rhodamine stains were negative for mycobacteria. QuantiFERON-TB Gold Plus results were positive. Chest radiograph did not demonstrate active pulmonary tuberculosis. The patient was treated for latent tuberculosis. When a patient presents with nodules on the lower legs with lobular lymphohistiocytic panniculitis with necrosis, evaluation for LTBI is necessary, followed by treatment if the evaluation is indicative of latent tuberculosis infection. The lesions associated with Bazin disease resolve spontaneously over several weeks to months. Nodular vasculitis may have similar presentation as Bazin disease but is typically not associated with tuberculosis.