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In 1897, Barker first described skin lesions evolving from erythematous macules to vesicles to necrotic ulcers in the setting of septicemia secondary to Pseudomonas aeruginosa.1 In the same year, Hitschmann and Kreibich coined the term ecthyma gangrenosum (EG) for this characteristic cutaneous manifestation of pseudomonal septicemia.2 Although P. aeruginosa is the classic pathogen in EG, other infectious organisms can produce clinically identical lesions (Table 62-1).3 Regardless of the causative organism, EG has a predilection for immunocompromised hosts, particularly individuals with neutropenia and hematologic malignancies.4 However, EG can also occur in previously healthy children, sometimes representing the initial presentation of a primary or acquired immunodeficiency. EG is currently considered as a morphologic pattern of cutaneous necrosis that results from occlusion of blood vessels by organisms proliferating within their walls, usually but not always associated with bacteremia or fungemia. EG tends to progress rapidly and has a high mortality rate without treatment, so early recognition and prompt administration of antimicrobial therapy are essential.
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Conditions that have been associated with EG in children are listed in Table 62-2. Approximately one-third of pediatric patients with EG have leukemia or aplastic anemia, and the occurrence of EG usually coincides with neutropenia related to the administration of chemotherapy or myeloablative regimens for hematologic stem cell transplantation. However, EG occasionally heralds the onset of leukemia in a previously healthy child.5 Additional predisposing factors for the development of EG in cancer patients and other immunocompromised hosts include occlusion or maceration of the skin, prior antibiotic therapy, treatment with systemic corticosteroids or other immunosuppressive medications, diabetes mellitus, and hypocomplementemia. Premature infants are also at higher risk of EG, particularly ...