Ecthyma Gangrenosum
Cary Chisholm, MD
Key Facts
Terminology
Sepsis (classically with Pseudomonas aeruginosa) with skin involvement
Clinical Issues
Single or multiple painful lesions in immunocompromised patients
Red macule that develops vesicles
Infiltration by neutrophils transforms vesicles into pustules
Necrosis develops with ulceration and eschar formation
Microscopic Pathology
Epidermal and dermal necrosis
Ulceration with serum crust
Neutrophil and lymphocytic infiltrate
Numerous bacteria in dermis
Vessel thrombosis with vasculitis
 This is ecthyma gangrenosum over the toe of a patient with pseudomonas sepsis. Black gangrenous changes  are seen on a red indurated base  . |
 This vessel is occluded by a thrombus  . Necrosis of the surrounding tissue has begun and neutrophils are infiltrating to the damaged tissue. |
TERMINOLOGY
Definitions
Sepsis (classically with Pseudomonas aeruginosa) with skin involvement
CLINICAL ISSUES
Epidemiology
Incidence
Arises in approximately 10% of patients with P. aeruginosa sepsis
Age
May affect patients of any age
Gender
No gender predilection
Site
Buttocks, perineum, genitalia, extremities
