Clinicopathologic Aspects of Ecthyma Gangrenosum in Pediatric Patients: A Case Series and Review of the Literature

Ecthyma gangrenosum (EG) is a well-described skin lesion classically associated with Pseudomonas septicemia in immunocompromised patients, but may also be caused by other bacterial and fungal organisms [1]. The lesions characteristically appear as small indurated papulovesicles progressing rapidly to necrotic ulcers with surrounding erythema and a central black eschar [2]. Ecthyma gangrenosum is caused by invasion of microorganisms into the media and adventitia of subcutaneous vasculature, precipitating a hemorrhagic occlusive vasculitis [2,3]. Although rare, the presence of EG is indicative of severe systemic infection with a potentially fatal prognosis. Mortality rates for EG range from 15% to as high as 77% based on reports in the literature [4-11]. Factors that are associated with higher mortality include neutropenia, septic shock, inappropriate or delayed antibiotic therapy, and resistant microorganisms [1,7-12]. We report three cases of Pseudomonas-associated EG that illustrate the assortment of clinical and histopathologic findings in this disease. We also review the literature on EG treatment and outcomes, which highlights the importance of timely diagnosis and appropriate antibiotic therapy. Ecthyma gangrenosum (EG) is a cutaneous lesion classically associated with potentially fatal pseudomonal septicemia in immunocompromised patients. Other bacterial and fungal pathogens have also been implicated in EG. Although EG typically occurs in neutropenic or immunocompromised patients, it can occasionally affect previously healthy children. The cutaneous findings are characteristic with small indurated papulovesicles progressing rapidly to necrotic ulcers with surrounding erythema and a central black eschar. While lesions can occur at any site, most are commonly found over the buttocks, perineum, limbs, and axillae. We describe three cases of EG in pediatric patients with a broad spectrum of clinical and histopathologic features, who responded to appropriate antibiotic treatment for Pseudomonas bacteremia. For patients with possible EG, it is very important to establish the diagnosis early so that appropriate systemic antibiotic therapy can be initiated to reduce morbidity and potential mortality.