Pediatric Gastroenteritis Clinical Presentation

The history and physical examination serve 2 vital functions: (1) differentiating gastroenteritis from other causes of vomiting and diarrhea in children, and (2) estimating the degree of dehydration. In some cases, the history and physical examination can also aid in determining the type of pathogen responsible for the gastroenteritis, though only rarely will this affect management.

• Diarrhea: Duration of diarrhea, the frequency and amount of stools, the time since last episode of diarrhea, and the quality of stools. Frequent, watery stools are more consistent with viral gastroenteritis, whereas stools with blood or mucus are indicative of a bacterial pathogen. Similarly, a long duration of diarrhea (>14 d) is more consistent with a parasitic or noninfectious cause of diarrhea.
• Vomiting: Duration of vomiting, the amount and quality of vomitus (eg, food contents, blood, bile), and time since the last episode of vomiting. When symptoms of vomiting predominate, one should consider other diseases such as gastroesophageal reflux disease (GERD), diabetic ketoacidosis, pyloric stenosis, acute abdomen, or urinary tract infection.
• Urination: Increase or decrease in frequency of urination measured by number of wet diapers, time since last urination, color and concentration of urine, and presence of dysuria. Urine output may be difficult to determine with frequent watery stools.
• Abdominal pain: Location, quality, radiation, severity, and timing of pain, per report of parents and/or child. In general, pain that precedes vomiting and diarrhea is more likely to be due to abdominal pathology other than gastroenteritis.
• Signs of infection: Presence of fever, chills, myalgias, rash, rhinorrhea, sore throat, cough. These may indicate evidence of systemic infection or sepsis.
• Appearance and behavior: Weight loss, quality of feeding, amount and frequency of feeding, level of thirst, level of alertness, increased malaise, lethargy, or irritability, quality of crying, and presence or absence of tears with crying.
• Antibiotics: History of recent antibiotic use increases the likelihood of Clostridium difficile.
• Travel: History of travel to endemic areas may make prompt consideration of organisms that are relatively rare in the United States, such as parasitic diseases or cholera.

• General: Weight, ill appearance, level of alertness, lethargy, irritability as depicted in the video below.

  Child with lethargy/poor general appearance.
• Head, ears, eyes, nose, and throat (HEENT): Presence or absence of tears, dry or moist mucous membranes, and whether the eyes appear sunken as shown in the videos below.

  Child with absent tears.

  Child with sunken eyes.
• Cardiovascular: Heart rate and quality of pulses
• Respiratory: Rate and quality of respirations (The presence of deep, acidotic breathing suggests severe dehydration.). See the video below.

  Child with hyperpnea (deep, acidotic breathing)
• Abdomen: Abdominal tenderness, guarding, and rebound, bowel sounds. Abdominal tenderness on examination, with or without guarding, should prompt consideration of diseases other than gastroenteritis.
• Back: Flank/costovertebral angle (CVA) tenderness increases the likelihood of pyelonephritis.
• Rectal: Quality and color of stool, presence of gross blood or mucus
• Extremities: Capillary refill time, warm or cool extremities
• Skin: Abdominal rash may indicate typhoid fever (infection with Salmonella typhi), whereas jaundice might make viral or toxic hepatitis more likely. The slow return of abdominal skin pinch suggests decreased skin turgor and dehydration (see the video below), while a doughy feel to the skin may indicate hypernatremia.

  Child with slow skin pinch (reduced skin turgor).

Identifying the specific etiologic agent responsible for the acute gastroenteritis rarely changes management. However, it may be helpful to differentiate between viral, bacterial, parasitic, and noninfectious causes of diarrhea.

By far, viruses remain the most common cause of acute gastroenteritis in children, both in the developed and developing world. Rotavirus represents the most important viral pathogen worldwide, responsible for 29% of all diarrhea-related deaths.^[5] In the United States, rotavirus is responsible for 410,000 office visits, 205,000-272,000 emergency department visits, and 55,000-70,000 hospitalizations each year.^[6] Rotavirus infection follows seasonal variation, with an increased incidence in winter and decreased incidence in summer.

Caliciviruses, astroviruses, and enteric adenoviruses make up the remainder of cases of viral gastroenteritis. According to the Centers for Disease Control and Prevention (CDC), Noroviruses (Norwalk-like viruses) are responsible for 50% of all food-borne outbreaks of gastroenteritis occurring in developed countries.^[3] Viral gastroenteritis typically presents with low-grade fever and vomiting followed by copious watery diarrhea (up to 10-20 bowel movements per day), with symptoms persisting for 3-8 days.^[3]

In developed countries, bacterial pathogens account for a small portion, perhaps 2-10%, of all cases of pediatric gastroenteritis. In the United States, the most important pathogens, in order of prevalence, are Campylobacter, Salmonella, Shigella, and enterohemorrhagic Escherichia coli (EHEC) species.^[3] Relative to viral gastroenteritis, bacterial disease is more likely to be associated with high fevers, shaking chills, bloody bowel movements (dysentery), abdominal cramping, and fecal leukocytes.

In developing countries, enterotoxigenic Escherichia coli (ETEC) remains the most important bacterial cause of acute gastroenteritis in children, followed by Campylobacter, Salmonella, and Shigella species, while also causing the majority of traveler's diarrhea cases in all age groups.^[7] Unlike other bacterial causes of gastroenteritis, ETEC is unlikely to cause dysentery.

Clostridium difficile has emerged as an important cause of antibiotic-associated diarrhea in children. Any antibiotic can trigger infection with C difficile, though penicillins, cephalosporins, and clindamycin are the most likely causes.^[3] Since 50% of neonates and young infants are colonized with C difficile, symptomatic disease is unlikely in children younger than 12 months.^[3]

Parasites remain yet another source of gastroenteritis in young children, with Giardia and Cryptosporidium the most common causes in the United States. Parasitic gastroenteritis generally present with watery stools but can be differentiated from viral gastroenteritis by a protracted course or history of travel to endemic areas.^[3]