Ecthyma gangrenosum in Adult
Characteristic purpura or eschars develop when proliferating microorganisms invade the adventitia and media of blood vessels, causing occlusion and ischemic necrosis. Bacterial organisms include P aeruginosa, other species of Pseudomonas, Escherichia coli, Klebsiella pneumoniae, Vibrio vulnificus, Serratia marcescens, Aeromonas hydrophila, Citrobacter freundii, Stenotrophomonas maltophilia, Morganella morganii, and Moraxella species.
Severe complications such as osteomyelitis may occur from infection with P aeruginosa. The course depends on the underlying disease, but once manifestations of shock appear, the patient may quickly and irreversibly decline. Disseminated intravascular coagulation (DIC) may appear with gram-negative sepsis. Most patients are systemically ill and have associated fever, chills, and hypotension. Diabetic patients, however, may have few symptoms early in the disease. EG is seen in approximately 1%-13% of patients with P aeruginosa sepsis. The mortality rate ranges from 18%-96%.
L08.0 – Pyoderma
17732003 – Ecthyma gangrenosum
Differential Diagnosis & Pitfalls
- Pyoderma gangrenosum – Lesions are more tender; patients are less likely to be systemically sick.
- Antiphospholipid antibody syndrome
- Necrotizing vasculitis
- Cutaneous anthrax – History of animal exposure; painful lymphadenopathy may be present.
- Acute meningococcemia – Can be more petechial, retiform, and purpuric.
- Calciphylaxis – Patient is likely to have history of renal failure; lesions are more retiform and can spread very quickly.
- Warfarin-induced skin necrosis – History of recent warfarin administration.
- Cocaine-induced skin necrosis
- Septic emboli – Lesions likely to be clustered with particular distribution based on vessels involved.
- DIC – Much more severely ill patient with significant laboratory abnormalities.
- Rickettsialpox – There is a history of preceding bite with more mild systemic malaise, fever, and headaches.
- Fusarium infection