Lysinibacillus massiliensis Panniculitis Masquerading as Erythema Nodosum: A Case Report

Lysinibacillus massiliensis, formerly Bacillus massiliensis, is an environmental Gram-positive bacillus that is generally non-pathogenic. Rare case reports in immunosuppressed patients have described sepsis with this organism. In this study, we report a case of L massiliensis as a cause of infectious panniculitis mimicking erythema nodosum after infusion of autologous adipose-derived stem cells in an immunosuppressed patient with refractory Crohn's disease. This case highlights the importance of care providers to consider exposures and host factors when interpreting culture results with otherwise benign organisms.