A 59-year-old white man with no significant medical history had a week of fever, chills, body aches, and diarrhea. A few days after the onset of these symptoms he noticed a painless vesicle on his left cheek. The following day the patient noticed a few more vesicles on his neck, underarms, and chest that slowly became painful and red, with some enlarging to become bullae and turning black. Soon thereafter, he presented to his local emergency department with severe sepsis. Further questioning revealed that he had no known drug allergies, and that he was an electrician who owned several dogs and 2 cows. He admitted tobacco and occasional alcohol abuse, but denied illicit drug use. He was not prescribed any medications before his hospitalization.
His vital signs at the time of presentation included a temperature of 100.9°F, blood pressure of 80/58 mm Hg, pulse rate of 135 beats/min, respiratory rate of 32 breaths/min, and an O2 saturation of 99% while breathing ambient air. Physical examination revealed painful vesicles with erythematous indurated borders on his bilateral axillae and chest with some of the lesions evolving into gangrenous ulcers with central necrotic areas (Fig. 1). His left cheek revealed a round, 1.5-cm, black eschar (Fig. 2). The rest of his physical examination was unremarkable.
Laboratory evaluation revealed a peripheral white blood cell (WBC) concentration of 1600/μL, with a differential count that revealed only 4% neutrophils, yielding an absolute neutrophil count of 64 cells/μL. No band forms were noted, and the rest of the leukocytes were composed of monocytes (74%) and lymphocytes (22%). He was also found to be in acute renal failure with a serum creatinine concentration of 3.1 mg/dL and urea nitrogen concentration of 45 mg/dL. Liver-associated enzymes and alkaline phosphatase values were within reference ranges.
Broad-spectrum antibiotics were administered and fluid resuscitation was initiated. He was transferred to our facility for further management that included a biopsy of one of the vesicles on the right side of the chest (Fig. 3).
What is your diagnosis?
Diagnosis: Ecthyma gangrenosum (EG) due to Pseudomonas aeruginosa bacteremia.
The patient's condition rapidly improved with a combination of fluid resuscitation and broad-spectrum antibiotics. His bone marrow also recovered with a peak peripheral WBC concentration of 12,500/μL with a normal differential count. After his transfer to our institution, the patient's blood and urine cultures grew P. aeruginosa at the transferring hospital, as did the culture of the skin biopsy. The pseudomonal isolates were pansusceptible to all tested antipseudomonal antibacterial agents. Once his culture results were known, his antibiotic regimen was pared down to intravenous piperacillin-tazobactam and oral ciprofloxacin. No underlying immunodeficiencies including human immunodeficiency virus 1 infection were noted, and he was eventually discharged to complete a 14-day course of 750 mg of oral ciprofloxacin taken twice daily.
Ecthyma gangrenosum is a rare, but highly characteristic, cutaneous manifestation of bacteremia often secondary to P. aeruginosa infection.1 It usually occurs in the setting ofimmunosuppression, particularly neutropenia. Ecthyma gangrenosum has occurred in patients with underlying malignancy, particularly leukemia, and those receiving immunosuppressive treatment. In addition, the relative immunosuppression associated with malnutrition, diabetes, and burns may have contributed to cases of EG.1,2 Although our patient was found to be neutropenic, because of his previously healthy state and rapid recovery of his WBC concentration, we suspect that his initial marrow suppression reflected his septic state and that it did not predate his pseudomonal infection.
Ecthyma gangrenosum is not common, occurring in only 1.3% to 6.0% of patients with Pseudomonas sepsis.3 As seen in Figure 1, beginning as isolated, painless, red, purpuric macules, EG skin lesions evolve to be painful, vesicular, indurated, and later, bullous or pustular.4 The central area becomes hemorrhagic and necrotic.4 The lesion then sloughs to form a gangrenous ulcer with a gray-black eschar and a surrounding erythematous halo as seen in Figure 2. The process evolves rapidly during a period of 12 to 24 hours.5 The lesions can range in size from 1 cm to greater than 10 cm in less than 24 hours, and are found preferentially in the groin, axilla, or trunk, but may occur anywhere.5 The skin lesions are slow to heal with time to resolution averaging 4 weeks.6
The cutaneous vasculitis of EG is characterized by bacterial invasion of the media and adventitia of vein walls deep in the dermis with sparing of the intima and lumen, and minimal inflammation as shown in Figure 3.4 Marked fibrin exudation and frank hemorrhage result from the bacterial invasion followed by bulla formation and necrosis of the dermis.4 Biopsy samples and Gram-stained material scraped from the base of the lesion should readily reveal the microorganisms.4
Multiple EG lesions and delay in initiating appropriate antibiotic coverage are associated with a poorer prognosis. The mortality rate associated with EG ranges from 18% to 96%.7 When EG occurs with neutropenia, the absolute neutrophil count correlates closely with the clinical outcome. Neutrophil counts lower than 500/μL during or after appropriate therapy predict a poor prognosis.7 Patients whose neutropenia resolves during the course of therapy demonstrate improved survival.1
Although P. aeruginosa is the most recognized pathogen of EG, numerous other organisms, including many other gram-negative bacilli, have been reported to cause clinically identical lesions.1,2,5,8 However, when faced with a patient with sepsis and skin lesions consistent with EG, resuscitation and antibiotic administration, including atleast 1 agent active against P. aeruginosa, should occur immediately.
1. Kim EJ, Foad M, Travers R. Ecthyma gangrenosum in an AIDS patient with normal neutrophil count. J Am Acad Dermatol
2. Khan FA, Vinjamuri M, Sarwari A. An immunocompromised patient with necrotic chin lesions. Clin Infect Dis
. 2006;42:242-243, [296-297].
3. Bodey GP, Jadeja L, Elting L. Pseudomonas
bacteremia. Retrospective analysis of 410 episodes. Arch Intern Med
4. Forkner CE Jr, Frei E 3rd, Edgcomb JH, et al. Pseudomonas
septicemia; observations on twenty-three cases. Am J Med
5. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis
6. Habif T. Clinical Dermatology: A Color Guide to Diagnosis and Therapy
. 4th ed. Philadephia: Mosby; 2004.
7. Greene SL, Su WP, Muller SA. Ecthyma gangrenosum: report of clinical, histopathologic, and bacteriologic aspects of eight cases. J Am Acad Dermatol
8. Reich HL, Williams Fadeyi D, Naik NS, et al. Nonpseudomonal ecthyma gangrenosum. J Am Acad Dermatol