Case
Presentation: A
75-year-old woman was consulted for a 1-week history of
diarrhea and fever.
She had an ischemic stroke about 5 years ago and then
became bedridden. One month earlier she had undergone a
plastic surgery for bedsore. During hospitalization, she
received intravenous antibiotics. Owing to some purulent
discharge from the wound, she was sent home from the hospital
with a prescription for oral clindamycin, 300mg four times a
day, which she had taken for 2 weeks. However, fever developed
since one week ago and an accompanied diarrhea for 3 days. She
was admitted to the plastic ward for the second time. After
taken the blood culture, treatment was started with
intravenous cefamezin. However, fever and diarrhea seemed to
be worse. A gastroenterologist was then consulted.
Physically, she was acute ill-looking.
The blood pressure was 160/90 mmHg, the pulse was 90/min, and the
temperature was 39。C. A 4cm surgical wound was found at sacral
area with scanty discharge. Her abdomen showed tenderness over
lower abdomen without rebounding pain. The other physical
examinations were unremarkable. Laboratory tests were
performed.
1. Hematologic Laboratory
Values:
|
RBC |
Hb |
Hct |
MCV |
Platelet |
WBC |
MCHC |
|
M/μL |
g/dL |
% |
fl |
k/μL |
k/μ |
g/dL |
On Admission |
4.78 |
14.2 |
42.6 |
90.1 |
320 |
17.8 |
33 |
|
Seg |
Eos |
Baso |
Mono |
Lym |
|
|
|
% |
% |
% |
% |
% |
|
|
|
89.5 |
3 |
0.1 |
1.9 |
5.5 |
|
|
2. Stool
Examination: Occult
blood: 3+ Stool WBC: Numerous / HPF Stool culture:
Negative
Course and
Treatment: A colonoscopy was performed
after consultation and it showed multiple raised, yellowish,
and plaque-like pseudomembranes over the entire colon (Figure
1
.). Clostridium difficile-toxin
was also recovered from the stool. Oral metronidazole 250mg
four times a day was prescribed under the diagnosis of
pseudomembranous colitis. Fever and diarrhea dramatically
subsided after a 10-day
treatment.
Case
Analysis: Pseudomembranous colitis is caused by
Clostridium difficile and develops in patients whose
gastrointestinal microbio has been changed by the use of
antibiotics. In healthy individuals, these normal microbio
effectively inhibits C. difficile by making host receptors
unavailable, competing for available nutrients, or producing
bacteriotoxins. The antibiotic clindamycin is the drug most
frequently associated with C. difficile infections, followed
by ampicillin and cephalosporin. At least two toxins of C.
difficile are recognized: toxin A, or enterotoxin, and toxin
B, or cytotoxin. Diagnosis generally requires isolation of the
organism from stool samples although C. difficile is difficult
to culture. Immunoassays for the toxins should be made to
confirm a positive toxin titer. Endoscopic observation of
pseudomembranes in the colon is the means for confirmative
diagnosis.
Diarrhea caused by pseudomembranous colitis may be a self
limited condition that resolves with fluid, electrolyte
support and cessation of antibiotics treatment. Oral
metronidazole is the drug of choice as it is less expensive
that oral vancomycin. It has antianaerobic properties and
avoids development of fecal enterococcal resistance to
vancomycin. Proper diagnosis is important to prevent the
development of pseudomembranous colitis and C. difficile
should be suspected in those who are immunosuppressed or other
risk-associated debilitated population groups with serious
diarrhea.
|