Dermatology Online Journal

Ecthyma gangrenosum: Presentation in a normal neonate
Ganesh Athappan MD, Athira Unnikrishnan MD, Satish Chandraprakasam MD
Dermatology Online Journal 14 (2): 17

Department of Medicine, Madurai Medical College, Maduari. ganeshathappan@gmail.com

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Ecthyma gangrenosum is a well recognized cutaneous manifestation of severe, invasive infection by Pseudomonas aeruginosa that is usually seen in immunocompromised and critically ill patients. There are isolated reports of its occurrence in normal healthy subjects. Other organisms besides Pseudomonas can sometimes produce a similar clinical picture. We report the development of ecthyma gangrenosum in an otherwise normal neonate.

Clinical synopsis

A 9-day-old term male neonate with a birth weight of 5 kg, delivered via lower-segment cesarean section, presented with multiple skin lesions that began on the fifth post-natal day. Red macules initially developed over the scalp with subsequent ulceration over 3-4 days. Similar lesions developed on the back, gluteal region, and both lower limbs. The skin lesions were accompanied by a continuous low-grade fever. There was no history of burns, drug intake, umbilical sepsis, catheterization, or diarrhea.

On physical examination an incision mark, acquired during cesarean section, was noted above the right tragus (Fig. 1). Skin examination showed erythematous macules, papules, nodules, vesicles and well-defined punched out gangrenous ulcers with raised erythematous borders and central black eschar. These were located over the scalp, back, gluteal regions, and both lower limbs (Fig. 2).

Figure 1	Figure 2

Laboratory investigations revealed an increased WBC count (n=20,000) with predominant neutrophils (76 %). Peripheral smear showed toxic granulations. Gram negative rods were demonstrated on gram staining of the pus. Cultures of blood, pus, and biopsy grew Pseudomonas aeruginosa. Skin biopsy revealed pauci-immune necrotizing vasculitis with hemorrhage and surrounding edema. The diagnosis of ecthyma gangrenosum associated with Pseudomonas infection was made. Chest radiography was normal. Infection by HIV was ruled out indirectly by ELISA testing of both parents.

Figure 3	Figure 4

Treatment was initiated with anti-pseudomonal antibiotics (piperacillin-tazobactam IV, 200mg every 8 hours for 21 days and amikacin IV, 25mg every 12 hours for 10 days). Silver sulfadiazine local application and surgical debridement were also instituted. This led to great improvement of the skin lesions (Fig. 4) by 3 weeks and clearing by 6 weeks.

Discussion

Ecthyma gangrenosum (EG) lesions characteristically begin as a painless red macules that evolve into papules and later hemorrhagic bullae. These rupture to produce gangrenous ulcers with black-gray eschar, surrounded by an erythematous halo [1]. The common sites of distribution of EG lesions are the gluteal or perineal region (57%), extremities (30%), trunk (6%), and face (6%) [2].

Breakdown of the mechanical defense barrier and impaired cellular or humoral immunity heighten the risk of infection by Pseudomonas aeuroginosa [2]. The organism localizes to the vessel wall by hematogenous seeding in septicemic patients and by direct inoculation in non-bacteremic ones. Subsequent proliferation of the organism in the vessel wall produces a necrotizing vasculitis by obstruction of the dermal vessels and dissolution of the elastic lamina of blood vessels by Pseudomonas elastase and exotoxin A. The characteristic painless, indurated ulcer with a central necrotic black eschar and surrounding erythema forms as a result [3].

Ecthyma gangrenosum typically occurs in the setting of hematological malignancies, malnutrition, severe burns, or immunodeficiency syndromes presenting with severe neutropenia. It is important to be aware that EG can occur in the absence of immunodeficiency. These cases develop as a complication of a break in the mechanical barrier of the skin or mucosa as seen in this case [2]. The absence of pain may lead to an underestimation of the severity of the disease and may lead to a failure in early initiation of treatment [4]. Ecthyma gangrenosum requires prompt diagnosis because early institution of anti-pseudomonal agents reduces the high mortality associated with pseudomonal sepsis [3].

Treatment should begin on the basis of clinical findings without waiting for laboratory confirmation. The recommended treatment combines an antipseudomonal penicillin (piperacillin) with an aminoglycoside. Combination therapy is far superior to monotherapy [5]. Further adjustment of antibiotics may be done after sensitivity results are determined.

In conclusion, physicians must be aware that EG and Pseudomonas septicemia can occur in both immunocompromised and healthy subjects so that prompt antipseudomonal therapy can be initiated.

References

1. Weinberg, AN & Swartz, MN. Gram negative coccal and bacillary infections. In: Fitzpatrick, TB, Eisen, AZ, Wolf, K et al. eds. Dermatology in General Medicine, 1993; Vol2: 2334 2349.

2. Elmariah SB, Ubriani R, Jmaes WD, Kageyama N, Fish F. Ecthyma Gangrenosum. Available at http://www.emedicine.com/derm/topic539.htm accessed on 24-05-07.

3. Singh TN, Devi KM, Devi KS. Ecthyma gangrenosum: A rare cutaneous manifestation caused by pseudomonas aeruginosa without bacteraemia in a leukaemic patient- A case report. Indian J Med Microbiol 2005;23:262-263 . PubMed [PubMed - indexed for MEDLINE]

4. Kao J, Low D.E, Gan SB. Soft tissue images. Ecthyma Gangrenosum : a deceptively benign skin lesion in febrile neutropenia. Canadian Journal of Surgery 2001;44(5):333. PubMed [PubMed - indexed for MEDLINE]

5. Chan YH , Chong CY, Puthucheary J, Loh T.F. Ecthyma Gangrenosum: a manifestation of pseudomonas sepsis in three pediatric patients. Singapore Med J 2006; 47(12): 1080-1083. PubMed [PubMed - indexed for MEDLINE]

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