Pulmonary Mycobacterium abscessus infection-induced erythema induratum

Erythema induratum (EI) is clinically characterized by recurrent crops of tender nodules on the lower legs and lobular panniculitis with granulomatous inflammation and pathologically characterized by vasculitis and focal fat necrosis. Currently, many authors consider EI to be a multifactorial disorder with diverse causes, including Mycobacterium tuberculosis and hepatitis C infection. Here, we report a case of a 65-year-old female with a 1-year history of recurrent crops of tender nodules and plaques on her bilateral lower legs. In addition, she had suffered from a chronic cough with sputum for 1 year and had contact history with pulmonary nontuberculous mycobacterial infection from her husband. The histopathological findings of the skin biopsies were consistent with the diagnosis of EI. Chest computed tomography revealed multiple lymphadenopathy and two sets of sputum cultures showed M. abscessus. After 2 months of anti-nontuberculous mycobacterial therapy with ciprofloxacin, the skin lesions resolved completely and there was no recurrence within the following year