Neutrophilic tuberculous panniculitis in a patient with polymyositis

The clinical spectrum of cutaneous M. tuberculosis infections is varied and atypical. Once a major cause of death, with the advent of antimicrobial drugs it had, until recently, been an uncommon consideration in the differential diagnosis of cutaneous disorders. Panniculitis can be caused by a variety of etiologic agents; however, only rarely has it been reported caused by tuberculosis. Herein, we describe a patient with an unusual case of neutrophilic panniculitis caused by M. tuberculosis that arose following corticosteroid therapy for presumptive polymyositis. This case illustrates the need to include mycobacterial infection in the differential diagnosis of panniculitis in immunocompromised patients, and the importance of early detection via microbiologic culture and histopathologic examination.