What is the appropriate management for an 18-month-old with Upper Respiratory Tract Infection (URTI) presenting with vomiting?

Causes of Vomiting in an 18-Month-Old with URTI

Vomiting in an 18-month-old with URTI is most commonly caused by the viral upper respiratory infection itself, with postnasal drip and cough triggering the gag reflex, though you must actively exclude more serious causes including acute gastroenteritis, otitis media, urinary tract infection, and less commonly, acute bacterial sinusitis or intracranial pathology.

Primary Mechanism in URTI

• Viral URTIs directly cause vomiting through multiple mechanisms: postnasal drip irritating the stomach, forceful coughing triggering the gag reflex, and swallowed mucus causing gastric irritation 1, 2
• The vomiting typically occurs intermittently, often after coughing episodes, and the child maintains adequate hydration between episodes 2
• Fever when present in uncomplicated viral URI tends to occur early (first 24-48 hours) along with constitutional symptoms, then respiratory symptoms become more prominent 3

Critical Differential Diagnoses to Exclude

Acute Gastroenteritis

• Viral gastroenteritis is the leading cause of acute vomiting in children and must be distinguished from URTI-associated vomiting 1
• Look for: predominant vomiting (more than 5 episodes in 24 hours), associated diarrhea, and signs of dehydration (abnormal capillary refill, abnormal skin turgor, abnormal respiratory pattern) 4, 5
• The vomiting in gastroenteritis is typically more persistent and severe than URTI-associated vomiting 1

Acute Otitis Media

• AOM commonly follows viral URTI, occurring on days 2-5 after URTI onset in up to two-thirds of young children with viral infections 3
• Examine for: red and bulging tympanic membrane, ear pain (child pulling at ear), irritability, and fever 3
• This age group (18 months) is at peak risk for AOM development 3

Urinary Tract Infection

• UTI presents with nonspecific symptoms in this age group, including vomiting, fever, and irritability without clear urinary symptoms 3, 6
• The prevalence is 0.1-1% in young children, with presentation often mimicking other infections 3
• Consider UTI if: fever without clear source, irritability, poor feeding, or vomiting persists beyond typical URTI course 6, 7

Acute Bacterial Sinusitis

• Suspect when URTI symptoms persist beyond 10 days without improvement or when there is severe onset with high fever (>39°C) and purulent nasal discharge for 3-4 consecutive days 3
• The concurrent presentation of high fever and purulent discharge early in illness distinguishes bacterial sinusitis from uncomplicated viral URI 3
• Most viral URIs resolve in 5-7 days; persistence suggests bacterial superinfection 3

Red Flag Signs Requiring Immediate Evaluation

Assess for life-threatening causes that present with vomiting 1:

• Bilious or bloody vomiting (suggests intestinal obstruction, intussusception, or malrotation with volvulus) 1
• Altered sensorium or excessive irritability (meningitis, encephalitis, intracranial pathology) 1
• Toxic/septic appearance (sepsis, severe bacterial infection) 1
• Severe dehydration (sunken eyes, decreased urine output, lethargy) 3, 4
• Inconsolable cry or bent-over posture (appendicitis, though rare at this age) 1

Management Approach

For URTI-Associated Vomiting

• Manage vomiting with small, frequent volumes of oral rehydration solution (5 mL every minute initially via spoon or syringe) 3
• Simultaneous correction of dehydration often lessens the frequency of vomiting 3
• Continue age-appropriate diet: full-strength formula or breast milk, with starches, cereals, yogurt, fruits, and vegetables for solid foods 3
• Replace each episode of vomiting with 10 mL/kg of ORS 3

When to Use Ondansetron

• Ondansetron (0.2 mg/kg oral; maximum 4 mg) is indicated when the child is unable to take oral fluids due to persistent vomiting 1
• Evidence shows ondansetron decreases vomiting rate, improves oral intake success, and reduces need for IV rehydration 4
• This allows successful oral rehydration in most children with mild to moderate dehydration 4

Common Pitfalls to Avoid

• Do not assume all vomiting with URTI is benign—always assess hydration status and exclude serious bacterial infections 1, 2
• Do not overlook UTI in this age group, as presentation is nonspecific and can mimic viral illness 3, 6
• Do not miss otitis media, which commonly complicates URTI and may be the actual cause of fever and vomiting 3
• Regular review in the early phases ensures fulminant illnesses are not overlooked and dehydration complications do not arise 2