Forgotten Infection Friday: Ecthyma Gangrenosum — The Rapidly Deadly Black Lesion

This episode explains ecthyma gangrenosum: a rapidly evolving, black necrotic skin lesion most classically caused by Pseudomonas aeruginosa invading blood vessels. It covers the pathophysiology, stages of progression, risk factors (immunocompromise, neutropenia, diabetes), and how it differs from ordinary diabetic foot ulcers. Key takeaways: urgent tissue biopsy and cultures for diagnosis, prompt broad-spectrum IV antibiotics and surgical debridement for source control, and early recognition to prevent sepsis, limb loss, and death.