A 2-year-old boy is brought to the emergency department following a 2-minute, generalized tonic-clonic seizure at home, which resolved spontaneously. The patient was behaving normally until last night, when he appeared to have abdominal pain and felt "warm to the touch." He has had no emesis but has been having frequent watery, loose stools over the past day that now contain blood and mucus. Temperature is 39.7 C (103.5 F), blood pressure is 100/62 mm Hg, pulse is 140/min, and respirations are 26/min. The patient is awake, active, and responsive. The pupils are equal and reactive, and the fundi appear normal. The oral mucosa is dry. The abdomen is soft with hyperactive bowel sounds and left lower quadrant tenderness to palpation. There is no hepatosplenomegaly or abdominal masses. Cranial nerve examination and deep tendon reflexes are normal. Which of the following is the most likely cause of this patient's symptoms?
Infectious bloody diarrhea | |||
Organism | History | Treatment | Complications |
Shiga-toxin–producing Escherichia coli* |
|
|
|
Shigella |
|
|
|
Campylobacter |
|
|
|
Salmonella |
|
|
|
*For example, E coli O157:H7. GBS = Guillain-Barré syndrome; HUS = hemolytic uremic syndrome. | |||
This patient has findings concerning for acute bacterial gastroenteritis (eg, fever, abdominal pain, bloody diarrhea), which can be caused by pathogens such as Escherichia coli O157:H7, Shigella, Campylobacter, and Salmonella. In children, seizures in the setting of acute bacterial gastroenteritis should raise concern for Shigella infection. Shigella sonnei is transmitted by ingestion of contaminated food or water and is sometimes implicated in outbreaks in community settings (eg, day care facilities) due to the low infectious dose required for person-to-person spread.
Shigella gastroenteritis presents abruptly with high fever, intestinal cramping, and stools that are initially watery before mucus and/or blood appears. Shigella preferentially involves the rectosigmoid region (ie, left lower quadrant), causing frequent, small-volume but bloody/mucoid diarrhea; tenesmus is also common. Seizure is a severe complication that can occur in children with Shigella infection. The seizure may be provoked by fever from the infection (ie, febrile seizure) or caused by enterotoxins produced by the organism itself. Other potential complications of Shigella include rectal prolapse (due to severe rectal inflammation), bacteremia (associated with increased fatality), and hemolytic uremic syndrome (HUS).
Diagnosis is confirmed by stool culture, and treatment involves supportive care (eg, rehydration), as well as antibiotic therapy for symptomatic patients. Symptoms typically resolve within a week. In contrast to E coli O157:H7 diarrhea, in shigellosis, antibiotics do not increase the risk of HUS.
(Choices A and B) Clostridium perfringens and enterotoxigenic E coli cause watery, nonbloody diarrhea. High-grade fever and associated seizures are unusual with these infections.
(Choice C) Intussusception can be a rare complication of viral gastroenteritis. Gastroenteritis symptoms may include watery diarrhea, fever, and seizures if dehydration is severe, whereas telescoping of bowel segments (ie, intussusception) due to hypertrophy of Peyer patches in the terminal ileum can result in episodic abdominal pain and bloody stools. However, ileal involvement causes right, not left, lower quadrant pain. In addition, a sausage-shaped abdominal mass is often palpable but is not present in this patient.
(Choice E) Ulcerative colitis, which is rare in children age <5, can cause abdominal pain, fever, and bloody diarrhea. However, symptom onset is typically gradual, and seizures are not seen.
Educational objective:
Gastroenteritis caused by Shigella sonnei presents acutely with high fever, abdominal cramping, and mucoid and/or bloody diarrhea. It may be associated with seizures in children.