The correct answer is A: Pseudomonas septicemia.
Discussion: The most striking morphologic feature seen is the presence of a thick, black-colored, necrotic eschar overlying both groin lesions. There are many causes of eschar formation, including all of the choices given. However, putting this case in perspective, one has to consider what is likely to cause escharotic lesions in a febrile, immunocompromised and likely neutropenic child. Under these circumstances, the logical conclusion is that the lesions depicted represent ecthyma gangrenosum, the most common etiology of which is Pseudomonas septicemia. This patient needs immediate bacterial and fungal culture of both the blood and skin lesions and emergent antibiotic administration suitable to cover for Pseudomonas aeruginosa.
The appearance and evolution of ecthyma gangrenosum (EG) is rather characteristic. These lesions are composed of indurated and often hemorrhagic vesico-papules or bullae of variable size that rapidly progress to necrotic areas, with surrounding erythema and surmounted by a black eschar. In young children, EG lesions are often accompanied by fever and diarrhea. EG lesions can occur at any site, although they are most commonly found over the buttocks or on the perineum (57%), or on the extremities (40%). Rarely, EG can involve the head and neck region.
In its most typical form, EG occurs in adult or pediatric patients who are already critically ill, well known to be immunocompromised and/or neutropenic, and frequently suffering from a hematologic malignancy. However, both adult and, more commonly, childhood cases have been described in ostensibly otherwise healthy individuals.[4-6] However, in some of these cases, an occult and previously undetected immunodeficiency state may be present, or a transient episode of neutropenia may be the cause. Thus, in all cases of EG without an obvious preexisting pathologic state, investigation for predisposing causes should be carried out. It should also be pointed out that EG heralding sepsis can accompany drug-induced neutropenia or agranulocytosis.[7,8]
EG is closely linked to Pseudomonas aeruginosa infection.[1,9,10] However, classic EG has been reported in association with a wide variety of other causative organisms, including (but not limited to): Escherichia coli, Citrobacter species, methicillin-resistant Staphylococcus aureus (MRSA), Candida albicans, and Fusarium species.[11,12] This diversity of causative microbes emphasizes the importance of broad empiric anti-infective coverage, early blood and tissue culture for microorganisms, and determination of susceptibilities in any patient presenting with EG. Additionally, nutritional support, temporary mitigation of immunocompromise (if possible), and surgical debridement of lesions may also play important roles in reducing potential morbidity and mortality.
1. Dorff GF, Geimer NF, Rosenthal DR, Rytel MW. Pseudomonas septicemia: Illustrated evolution of its skin lesion. Arch Int Med. 1991;128:591–595.
2. Almeida JF, Sztajnbok J, Troster EJ, Vaz FA. Pseudomans aeruginosa septic shock associated with ecthyma gangrenosum in an infant with agannaglobulinemia. Rev Inst Med Trop S Paulo. 2002;44:167–169.
3. Funk E, Ivan D, Gillenwater AM. Ecthyma gangrenosum: an unusual cutaneous manifestation of the head and neck. Arch Otolaryngol Head Neck Surg. 2009; 135:818–820.
4. Goolamali SI, Fogo A, Killian L, et al. Ecthyma gangrenosum: an important feature of pseudomonal sepsis in a previously well child. Clin Exp Dermatol. 2009;34:80–82.
5. Athappan G, Unnikrishnan A, Chandraprakasam S. Ecthyma gangrenosum: presentation in a normal neonate. Dermatol Online J. 2008; 14(2):17.
6. Zomorrodi A, Wald ER. Ecthyma gangrenosum: considerations in a previously healthy child. Pediatr Infect Dis J. 2002;21:1161–1164.
7. Fairhurst DA, Pollock B. Ecthyma gangrenosum presenting in diclofenac(Drug information on diclofenac) induced neutropenia. J Eur Acad Dermatol Venereol. 2006;20:868–869.
8. del Giudice P, Cua E, Bernard E, et al. Pseudomonas aeruginosa ecthyma gangrenosum and facial cellulitis complicating carbimazole(Drug information on carbimazole)-induced agranulocytosis. Arch Dermatol. 2006;142:1663–1664.
9. Demircioğlu F, Oren H. Ecthyma gangrenosum: Sign of Pseudomonas aeruginosa bacteremia. Pediatr Hematol Oncol. 2008;25:369–370.
10. Frantzeskaki F, Betrosian AP. Ecthyma gangrenosum: a rare manifestation of Pseudomonas aeruginosa sepsis in a critically ill adult patient. Eur J Dermatol. 2008;18:345–346.
11. Patel JK, Perez OA, Viera MH, et al. Ecthyma gangrenosum caused by Escherichia coli bacteremia: a case report and review of the literature. Cutis. 2009;84:261–267.
12. Tsuchiyama K, Okuyama R, Ogawa E, et al. Ecthyma gangrenosum with Citrobacter freundii infection. J Eur Acad Dermatol Venereol. 2009;23:709–710.
13. Khalil BA, Baillie CT, Kenny SE, et al. Surgical strategies in the management of ecthyma gangrenosum in paediatric oncology patients. Pediatr Surg Int. 2008;24:793–797.