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difficile is a gram-positive, toxin-producing anaerobic rod that is the causative agent of pseudomembranous colitis.
The most common antibiotics associated with C. difficile in children reflect antibiotics most commonly used in the
outpatient setting: penicillins, cephalosporins, clindamycin, and macrolides. Other risk factors include use of
feeding tubes, proton pump inhibitors, immunocompromise, and recent hospitalization.
Colitis with C. difficile varies widely in severity. Typically, profuse watery or mucoid diarrhea begins after
several days of antibiotic therapy. Many older children complain of crampy abdominal pain. On examination, the
usual findings include fever and diffuse abdominal tenderness. Often, the WBC count rises above 15,000/mm3.
The stool may be guaiac-positive or frankly bloody; leukocytes (by stool microscopy or by measuring stool
lactoferrin) are found in approximately 50% of patients. An etiologic diagnosis requires the identification of C.
difficile toxin in the stool; recovery of the organism on culture is suggestive but not sufficient. The diagnosis is
more difficult in children less than 2 years of age, who can have asymptomatic intestinal colonization by toxigenic
C. difficile. If C. difficile colitis goes unrecognized and untreated, complications, including toxic megacolon,
perforation, and peritonitis, may develop. Case fatality rates as high as 10% to 20% were described before the
introduction of specific treatments.
Treatment of asymptomatic carriers is not recommended. Mild cases without fever or other systemic signs of
infection may resolve with discontinuation of the inciting antibiotic(s) and supportive care. Treatment of moderate
to severe infection, defined as pyrexia, voluminous diarrhea, dehydration, colitis, or leukocytosis, warrants
systemic therapy.
Oral metronidazole (30 mg/kg/day in four divided doses; maximum: 2 g/day) is the first-line choice for initial
treatment of mild/moderate disease and for treatment of the first relapse. Oral vancomycin (40 mg/kg/day in four
divided doses; maximum: 500 mg/day) can be used for refractory cases, as up to 20% of patients may relapse.
Severe cases may require both oral vancomycin and intravenous metronidazole (same dose as for oral
administration). Treatment should continue at least 10 days. Antidiarrheal agents should be avoided. Contact
precautions should be used. Alcohol-based hand hygiene products do not kill spores; instead, providers should
wash their hands with soap and water.

Intra-Abdominal Abscesses
The most common cause of intra-abdominal abscesses in childhood will be from perforated appendicitis. Blood
cultures rarely are positive unless the child is immunocompromised or toxic appearing. These infections are
polymicrobial, and cultures often grow a combination of gram-negative enterics and anaerobes. As such, broadspectrum antimicrobial coverage should be offered. The Infectious Disease Society of America has published
guidelines for empiric therapy for children with complicated intra-abdominal infections. Monotherapy has been

found to be equivalent in terms of outcomes to combination therapy. Single-agent regimens include piperacillintazobactam, and carbapenems (e.g., meropenem, ertapenem) for children with community-acquired infections.
Recommended multidrug regimens include a third-generation cephalosporin with metronidazole; metronidazole or
clindamycin with an aminoglycoside, with or without ampicillin.

GENITOURINARY INFECTIOUS EMERGENCIES
Urinary tract infections (UTIs) and renal abscesses are discussed in this section. The diagnosis and management of
children with pelvic inflammatory disease are covered in Chapter 92 Gynecology Emergencies .

Urinary Tract Infections
CLINICAL PEARLS AND PITFALLS
The most common pathogen causing UTIs is E. coli; in many regions, over 50% of E. coli isolates
from the urinary tract are resistant to amoxicillin and/or TMP-SMZ.
UTIs are on the differential diagnosis of fever of unknown origin and of failure to thrive in infants.
Most children outside the neonatal period who have UTIs can be managed in the outpatient setting.
Isolation of S. aureus from a urinary culture should prompt evaluation for a renal abscess.
Current Evidence
Infections occur along the urinary tract from the tip of the urethra to the renal parenchyma. Clinical syndromes that
may accompany infections include urethritis, cystitis, and pyelonephritis. Bacteriuria refers to the presence of