A 30 year history of panniculitis.

The differential diagnosis of panniculitis may be challenging due to the uniform clinical presentation of different panniculitis subsets. We describe a 45-year-old woman with a 30 year history of panniculitis, who had repeatedly failed to fulfill diagnostic criteria for various panniculitis subsets. Finally, erythema induratum was diagnosed and she was successfully treated with antituberculous chemotherapy. The wide spectrum of histological alterations of chronic erythema induratum as well as the sensitivity of polymerase chain reaction for Mycobacterium tuberculosis in erythema induratum lesions is discussed.