Vol. 21, No. 4, 2009
Received January 19, 2009, Revised February 9, 2009, Accepted for
publication February 10, 2009
Reprint request to: Joo Young Roh, M.D., Department of Dermatology,
Gachon University of Medicine and Science, Gil Medical Center,
1198, Guwol-dong, Namdong-gu, Incheon 405-760, Korea. Tel: 82-
32-460-2000, Fax: 82-32-460-2001, E-mail: firstname.lastname@example.org
Ann DermatolVol. 21, No. 4, 2009
Ecthyma Gangrenosum: A Rare Cutaneous
Manifestation Caused by Stenotrophomonas maltophilia in
a Leukemic Patient
Young Min Son, M.D., So Young Na, M.D., Hye Young Lee, M.D., Jin Ok Baek, M.D.,
Jong Rok Lee, M.D., Joo Young Roh, M.D.
Department of Dermatology, Gachon University of Medicine and Science, Gil Medical Center, Incheon, Korea
Ecthyma gangrenosum (EG) is a well-recognized cutaneous
infection that most commonly affects immunocompromised
patients. It typically occurs on the extremities, or in gluteal
and perineal regions. Although Pseudomonas aeruginosa is
the most well-known pathogen causing EG, other organisms
have been reported to cause EG. Herein we report a rare case
of ecthyma gangrenosum presenting as aggressive necrotic
skin lesions in perioral and infraorbital areas in a 47-year-old
patient with acute myelocytic leukemia after allogeneic
bone marrow transplantation. It was caused by Stenotropho-
monas maltophilia, which is an aerobic, gram-negative
pathogen that has been associated only rarely with cuta-
neous disease. Blood culture and tissue culture were positive
for S. maltophilia. Histological examination revealed numer-
ous tiny bacilli in the dermis and perivascular area. Early rec-
ognition of skin lesions caused by S. maltophilia is important
to decrease associated mortality in immunosuppressed
patients. (Ann Dermatol 21(4) 389∼∼392, 2009)
Ecthyma gangrenosum, Stenotrophomonas maltophilia
Ecthyma gangrenosum (EG) is a well known cutaneous
manifestation that most commonly affects immunosup-
pressed and burn patients1,2. It usually occurs as a result of
bacteremia or, rarely, as a primary cutaneous lesion. The
lesions are present in the gluteal and perineal regions or
on the extremities, but they can occur anywhere on the
body1,3,4. Most cases of ecthyma gangrenosum are asso-
ciated with Pseudomonas aeruginosa bacteremia5,6. But
numerous other organisms have been reported to cause
Stenotrophomonas maltophilia is an aerobic gram-neg-
ative bacillus that is a frequent colonizer of fluids used in
hospital settings. The incidence of S. maltophilia infection
has been increasing. Until now, one case of S. maltophilia
infection, paronychia, have been reported in Korea7, and
several cases of mucocutaneous, skin and soft tissue in-
fection have been reported abroad8-10.
It is important to identify early the skin lesions caused by
S. maltophilia because it is associated with a high mortal-
ity in immunocompromised hosts.
A 47-year-old man with a history of AML stage M2 was
admitted to the hematology-oncology department due to
high fever. Nine days after an allogeneic bone marrow
transplantation, he developed a 38.8oC-high fever. Intrave-
nous cefazolin, teicoplanin, metronidazole, and mer-
openem were maintained after admission. The next day,
he developed rapid, progressive, severe, edematous, er-
ythematous, and necrotic plaques with bullae formation
around the lips (Fig. 1) and was referred to the dermatol-
ogy department for evaluation of the skin lesions. A skin
biopsy from a perioral necrotic hemorrhagic vesicle with
blood culture, fungus culture, and open pus culture was
performed. Two days later, he suffered from bradycardia,
YM Son, et al
Fig. 2. (A) Skin biopsy specimen showing subepidermal blister with hemorrhage and dermal edema with vascular congestion (H&E,
×100). (B) Perivascular cuffing with basophilic deposits accompanied by a mixed inflammatory infiltrate of lymphocytes and histiocytes
in dermis. Intravascular thrombosis was present with endothelial swelling (H&E, ×200).
Fig. 3. Numerous gram-negative bacilli surround papillary
dermal vessels and infiltrate the tissue (Gram stain, ×1,000).
Fig. 1. Severe edematous erythematous necrotic plaques with
perioral bullae formation.
hypotension, and respiratory distress and expired. Blood
and tissue culture results revealed S. maltophilia which
was resistant to the antibiotics that he had been treated
with; this pathogen was sensitive to trimethoprim-sulfame-
thoxazole. Although an autopsy was not done, the cause
of death was probably sepsis caused by S. maltophilia.
The histopathologic findings included a sub-epidermal
blister with hemorrhage and dermal edema with vascular
congestion (Fig. 2A). There was perivascular cuffing with
basophilic deposits accompanied by a mixed inflam-
matory cell infiltrate of lymphocytes and histiocytes in the
dermis. Basophilic deposits suggestive of bacterial colo-
nies surrounded the affected vessels and were scattered in
the interstitial dermis. In addition, intravascular thrombo-
sis was present with endothelial swelling (Fig. 2B). A tis-
sue Gram stain revealed basophilic deposits to be collec-
tions of gram-negative bacilli which were subsequently
identified as S. maltophilia on blood culture (Fig. 3).
EG is a rare necrotizing vasculitis3 and a well recognized
manifestation that occurs in debilitated persons who are
suffering from leukemia, in severely burned patients, in
pancytopenia or neutropenia, and in patients with a func-
tional neutrophilic defect, terminal carcinoma, or other se-
vere chronic diseases1. It most commonly affects im-
munocompromised and burn patients but it also occurs in
the perineal area of healthy infants after antibiotic therapy
in conjunction with maceration of the diaper area1,3. The
skin lesions of ecthyma gangrenosum are the manifes-
Ecthyma Gangrenosum: A Rare Cutaneous Manifestation Caused by Stenotrophomonas maltophilia in a Leukemic Patient
Vol. 21, No. 4, 2009
tation of a necrotizing vasculitis3. The lesion characteristi-
cally begins as an erythematous nodule, macule, vesicle,
or bullae and evolves into gangrenous ulcerations with
black eschar and a surrounding rim of erythema6,11,12. The
vesicles, initially filled with serous fluid, appear on the
surface of the edematous skin, and then coalesce to form
large bullae. The bullae slough away, leaving ulcerated,
necrotic centers with erythematous halos3,13. The matura-
tion of the lesion is very rapid and often occurs in less
than 24 hours as in our patient11. Fifty seven percent of
skin lesions were located in the gluteal region, 30% on
the extremities including the axillae, and 6% on the trunk.
Facial involvement is unusual, occurring only in 6% of
The pathogenic mechanism of EG is unknown, but several
possible mechanisms have been suggested6. Two mecha-
nism of EG have been well described. In classic bactere-
mic EG, the skin lesions are considered to represent
blood-borne metastatic seeding of an organism into the
skin5,6,14. Our patient also revealed a positive blood cul-
ture result. In nonbacteremic EG, the lesion is located at
the site of entry or inoculation of the organism into the
skin5,6. Some investigators have suggested that non-
bacteremic EG may be an early type of EG6.
Although Pseudomonas aeruginosa is the most common
pathogen of EG-associated bacteremia, other organisms
have been reported. The most commonly reported one are
Citrobacter freundii, Aeromonas hydrophila, and Escheri-
chia coli3,5,15. Our case is unique in that the patient’s EG
lesion was caused by a rarely isolated gram-negative ba-
cillus, S. maltophilia.
Histopathologically, EG is characterized by epidermal ne-
crosis with hemorrhage and dermal infarction, usually ac-
companied by a mixed inflammatory cell infiltrate of lym-
phocytes, hisitocytes and neutrophils1,2. In general, acute
mixed inflammatory cell infiltration and vascular pro-
liferation are seen in the dermis, often involving the sub-
cutaneous tissue6. Gram negative bacilli may be seen in
the dermis and involving the media and adventitia of ven-
ules, but not the intima. Vasculitis and thrombosis may be
present2. Since numerous Gram-negative basophilic bacilli
were observed, mainly in the dermis and perivascular area
in our case, skin lesions are speculated to be secondary to
Early diagnosis and effective therapy are essential in the
management of EG6. Treatment of EG involves the use of
appropriate systemic antibiotics according to biopsy and
blood culture results11. A combination of an aminoglyco-
side and an anti-pseudomonal β-lactam antibiotics is rec-
ommended for treatment of both bacteremic and non-
bacteremic EG6,11. Nonbacteremic patients with EG have
relatively low mortality, ranging from 7% to 15% in a re-
cent series, but the mortality rate in patients with bacter-
emia ranges from 38% to 96%3. The physical finding of
bullous cellulitis is associated with higher mortality, and
the number of skin lesions is positively correlated with the
severity of the disease3. Other prognostic factors include
the time of onset of antibiotic therapy and the patient’s re-
sponse to therapy11.
Stenotrophomonas maltophilia, formerly named Xantho-
monas maltophilia and Pseudomonas maltophilia, is an
aerobic, gram-negative bacillus and has emerged as an im-
portant opportunistic nosocomial infection often asso-
ciated with central venous catheter-related bacteremia16,17.
It is a frequent colonizer of fluids used in the hospital set-
ting, such as nebulizers, dialysis machines, water baths
and intravenous fluids8. Colonization with S. maltophilia
is seen to a greater degree in patients treated with broad-
spectrum antibiotics as in our patient10. It grows slowly in
disinfectant agents and has a high rate of mutation, which
can confer resistance to antibiotics16. Resistance to be-
ta-lactams, carbapenems, aminoglycosides, and quino-
lones is well known16.
Skin and soft tissue manifestations of S. maltophilia in-
fection are becoming increasingly well recognized8,9, and
are most frequently associated with posttraumatic,
post-surgical, or burn-related wounds and chronic cuta-
neous ulcers16. Clinical manifestations include cellulitis,
cellulitis-like skin lesions, infected mucocutaneous ulcers,
EG and paronychia7-10,18. The route of transmission is
mainly unknown but it seems likely that invasion takes
place via defects in mucous membranes and by colo-
nization of central venous catheters10.
Infections with S. maltophilia can be life-threatening be-
cause of its pathogenicity, intrinsic resistance to many an-
tibiotics and the general condition of patients affected16.
Jang et al.18 found that among their 32 cases who did not
receive appropriate antimicrobial therapy, none survived.
Trimethoprim-sulfamethoxazole (TMP-SMX) is recom-
mended as the agent of choice for therapy of S. malto-
philia infection as it is found to be active against most
strains although resistance is increasing. Ticarcillin-clav-
ulanate is noted to have good activity and is suggested as
the agent of choice in individuals intolerant of TMP-
The recovery from S. maltophilia infection is dependent
on treatment with appropriate antibiotics, reversal of mye-
losuppression and removal of intravenous catheters8,14.
Hematologic malignancy, transplantation, neutropenia,
immunosuppressive therapy and a high severity of illness
score (based on temperature, presence of hypotension,
mental status and need for ventilatory support) were im-
YM Son, et al
portant prognostic factors8,20. Early diagnosis and appro-
priate antibiotic therapy are also critical for improving the
prognosis of S. maltophilia infection8,18.
S. maltophilia skin infection should be included in the list
of differential diagnoses for skin lesions in neutropenic pa-
tients, especially the ones with an underlying hematologic
malignancy, who have received recent chemotherapy and
broad spectrum antibiotics.
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