The case of the blue wound: Atypical drainage in chronic leg ulcers

The appearance of blue drainage from a chronic wound is uncommon but clinically significant. This case report describes a 37-year-old woman with chronic bilateral venous leg ulcers and new-onset light blue wound drainage, without classic signs of infection. While blue exudate is typically associated with Pseudomonas aeruginosa , cultures revealed a polymicrobial infection with gram-negative organisms, including Providencia stuartii , Klebsiella oxytoca/Raoultella ornithinolytica , Morganella morganii , and Proteus mirabilis , as well as group B streptococcus , but no Pseudomonas . The patient developed systemic symptoms, and her condition improved with empiric oral antibiotics. This case underscores the importance of microbiological evaluation in atypical wound presentations and cautions against overreliance on visual cues when identifying pathogens. Blue wound drainage, even in the absence of Pseudomonas , may signal a high bacterial burden and warrants prompt investigation and treatment.