Acinetobacter baumannii-associated skin and soft tissue infections: recognizing a broadening spectrum of disease

Abstract

Background: Acinetobacter baumannii is gaining importance as a cause of nosocomial infections, but its role in skin and soft tissue infection (SSTI) is not well defined. As a result of the outbreak of A. baumannii occurring in military personnel in Iraq and Afghanistan, reports of severe wound infections and SSTI caused by this pathogen are increasing in frequency.

Methods: We describe four cases of monomicrobial and polymicrobial A. baumannii-associated necrotizing SSTI accompanied by A. baumannii bacteremia and offer a review of similar experiences published in the literature.

Results: Our comparative analysis reveals four unique features associated with necrotizing SSTI associated with A. baumannii: i) Occurs in hosts with underlying comorbidities (e.g., trauma, cirrhosis); ii) is often accompanied by bacteremia; iii) multiple drug resistance and the presence of co-pathogens frequently complicated treatment (64% of cases); iv) the cases reported here and in our review required surgical debridement (84% of cases) and led to substantial mortality (approximately 30%).

Conclusions: As the prevalence of A. baumannii continues to increase in our health care system, SSTIs caused by this organism may become more common. Clinicians must be aware that the spectrum of disease caused by A. baumannii could include severe necrotizing SSTI and that vigilance for potential complications is necessary.

FIG. 1.

Ecchymosis and sloughing of skin in flank and lower extremity. Extensive debridement performed.

FIG. 2.

Soft tissue biopsy revealed the presence of bacteria, thrombosis of capillaries, and necrosis of subcutaneous fascia and intrafascicular bundles.

FIG. 3.

Cellulitis caused by Acinetobacter baumannii. There is characteristic edematous “peau d'orange” erythema with associated vesicles that may coalesce to form non-hemorrhagic bullae.