What is the best course of action for a 2-year-old with vomiting and fever?

Management of a 2-Year-Old with Vomiting and Fever

Begin with systematic exclusion of serious bacterial infections—particularly urinary tract infection, pneumonia, and meningitis—while simultaneously initiating oral rehydration therapy, as viral gastroenteritis is the most common diagnosis but cannot be assumed until life-threatening conditions are ruled out. 1, 2

Immediate Assessment Priorities

Rule Out Critical Red Flag Conditions First

• Check for altered consciousness, severe lethargy, or irritability immediately to exclude meningitis or bacterial sepsis, as many children with serious bacterial infections may appear well initially 1, 2
• Assess for respiratory distress, cyanosis, hypoxia, or rales on auscultation, as pneumonia frequently presents with fever and vomiting without prominent respiratory symptoms 1
• Document rectal temperature (fever defined as ≥38.0°C/100.4°F) and verify if antipyretics were given in the previous 4 hours, as this may mask fever severity 2

Evaluate Dehydration Status Using Physical Examination

The physical examination is the most reliable method for assessing hydration status 3:

• Mild dehydration (3-5% deficit): increased thirst, slightly dry mucous membranes 1
• Moderate dehydration (6-9% deficit): loss of skin turgor, dry mucous membranes 1
• Severe dehydration (≥10% deficit): severe lethargy, prolonged skin tenting, cool extremities, decreased capillary refill 1
• The three most useful predictors of 5% or more dehydration are abnormal capillary refill, abnormal skin turgor, and abnormal respiratory pattern 4

Diagnostic Evaluation Algorithm

Urinary Tract Infection Screening (Highest Priority)

Obtain urinalysis and urine culture in all febrile 2-year-olds with vomiting and no obvious source of infection, as UTI is the most common serious bacterial infection in this age group and frequently presents with nonspecific symptoms including vomiting 5, 1, 6:

• Collect urine by catheterization (preferred method due to lower contamination rates) rather than clean catch or bag specimens 2
• Use a positive test result for urine leukocyte esterase, nitrites, leukocyte count, or Gram's stain to make a preliminary diagnosis 5
• Obtain urine culture when starting antibiotics for preliminary UTI diagnosis 5
• Even if dipstick urinalysis is negative, obtain a urine culture if UTI is still suspected, as no clinical feature effectively excludes UTI 5

Pneumonia Evaluation

Obtain chest radiograph if any of the following are present 5, 2:

• Cough
• Hypoxia
• Rales or crackles on auscultation
• High fever (≥39°C/102.2°F)
• Fever duration greater than 48 hours
• Tachycardia and tachypnea out of proportion to fever

Do not order chest radiograph if the child has wheezing or high likelihood of bronchiolitis 5, 2

Meningitis Considerations

For a 2-year-old, lumbar puncture is generally not required unless specific signs suggest meningitis (altered consciousness, neck stiffness, severe lethargy, irritability) 2, 6

Treatment Protocol

Step 1: Immediate Fluid Management

Begin oral rehydration therapy immediately with small, frequent volumes (5 mL every minute) using a spoon or syringe, as simultaneous correction of dehydration often lessens vomiting frequency 1:

• For mild dehydration, half-strength apple juice followed by the child's preferred liquids is as effective as traditional oral rehydration solutions 3
• For moderate dehydration, use oral rehydration solutions 3
• Replace ongoing vomit losses with appropriate volumes of oral rehydration solution 1
• Oral or nasogastric rehydration is equally efficacious as intravenous rehydration for mild to moderate dehydration 4, 3

Step 2: Antiemetic Use

Administer ondansetron (0.2 mg/kg oral; maximum 4 mg) if the child is unable to tolerate oral rehydration due to persistent vomiting 7, 4:

• Children receiving ondansetron are less likely to vomit, have greater oral intake, and are less likely to require intravenous rehydration 4, 3
• Mean Emergency Department stay is shorter with ondansetron use, and serious side effects are rare 4

Step 3: Fever Control

Use acetaminophen (paracetamol) as first-line antipyretic for symptomatic management, with the goal of improving the child's comfort rather than normalizing body temperature 6:

• Never use aspirin in children under 16 years due to Reye's syndrome risk 1
• Physical cooling methods (fanning, cold bathing, tepid sponging) are not recommended and cause discomfort 6

Step 4: Dietary Management

Once rehydration is achieved, immediately resume age-appropriate diet—do not withhold food 1:

• Recommended foods include starches, cereals, yogurt, fruits, and vegetables 1
• Avoid foods high in simple sugars and fats 1

Hospitalization vs. Outpatient Management

Send to Hospital Immediately If:

• Respiratory distress or cyanosis 1
• Altered consciousness or severe lethargy 1
• Prolonged vomiting >24 hours 1
• Signs of septicemia 1
• Severe dehydration (≥10% deficit or signs of shock) 3
• Bilious or bloody vomiting (suggests intestinal obstruction) 7, 8
• Failure to respond to oral rehydration therapy plus antiemetic 3

Outpatient Management Appropriate If:

• Good general condition 6
• Normal urinalysis (or pending culture) 6
• Mild to moderate dehydration successfully treated with oral rehydration 6
• Parents able to monitor and return if deterioration occurs 6

Follow-Up and Parent Education

Reevaluate within 24 hours for all children managed on an outpatient basis 6:

• Instruct parents to return immediately if: child becomes irritable or lethargic, decreased urine output, intractable vomiting develops, persistent diarrhea continues, worsening general condition, appearance of skin spots, respiratory distress, feeding refusal, or excessive somnolence 1, 6
• If fever persists beyond 3 days or worsens, return for reassessment 9

Critical Pitfalls to Avoid

• Never assume viral gastroenteritis without systematically excluding UTI, pneumonia, and meningitis, as these can present identically 1
• Never rely solely on clinical appearance—58% of infants with bacteremia or bacterial meningitis appear clinically well 2
• Never use antidiarrheal agents, as they shift focus away from appropriate fluid therapy and cause serious complications 1
• Never delay oral rehydration—early aggressive oral rehydration prevents progression to severe dehydration 1
• Never fail to consider recent antipyretic use, which may mask fever and severity 2
• Never perform routine laboratory or radiologic screening without specific clinical indications, as the diverse causes of vomiting make routine testing inappropriate 7