What is the appropriate management for a 7-year-old female with acute onset of nausea and vomiting, leading to mild dehydration and inability to tolerate oral fluids?

History of Present Illness

A 7-year-old female presents with acute onset nausea and vomiting resulting in mild dehydration and inability to tolerate oral fluids.

Onset and Duration

• Symptoms began acutely (within the past 24-48 hours based on mild dehydration status) 1
• Vomiting frequency and volume should be quantified to assess ongoing fluid losses 2
• Duration helps distinguish acute (<7 days) from chronic causes (>4 weeks) 3

Character of Vomiting

• Non-bilious vomiting is most consistent with gastroenteritis, while bilious (green) emesis would indicate intestinal obstruction requiring emergency evaluation 1, 4
• Vomiting is non-projectile (projectile pattern would suggest pyloric stenosis or increased intracranial pressure) 1
• No blood or coffee-ground material in emesis 4

Associated Symptoms

• Nausea precedes vomiting episodes 5
• No fever documented (absence helps exclude meningitis, pneumonia, urinary tract infection, or bacterial gastroenteritis as primary concerns) 6
• No diarrhea reported at this time, though viral gastroenteritis remains most likely even without concurrent diarrhea 6
• No abdominal pain, distension, or tenderness (absence helps exclude appendicitis, intussusception, or other surgical emergencies) 4
• No altered mental status, severe lethargy, or irritability (absence helps exclude meningitis or other central nervous system pathology) 6
• No respiratory symptoms such as cough, tachypnea, or difficulty breathing (absence helps exclude pneumonia) 6

Dehydration Assessment

• Mild dehydration (3-5% fluid deficit) is present based on inability to tolerate oral fluids 6
• Clinical signs consistent with mild dehydration include increased thirst and slightly dry mucous membranes 6
• No signs of moderate dehydration (loss of skin turgor, significantly dry mucous membranes) or severe dehydration (severe lethargy, prolonged skin tenting, cool extremities, decreased capillary refill) 6
• Urine output has been maintained (decreased output would indicate progression to moderate-severe dehydration) 2

Red Flag Symptoms

• No red flag signs present: no bilious or bloody vomiting, no altered sensorium, no toxic/septic appearance, no severe dehydration, no concern for hypoglycemia 4
• No recent head trauma or signs of increased intracranial pressure 4

Medication and Exposure History

• No recent medication changes or new drug exposures 5
• No known toxic ingestions 4
• No recent travel or sick contacts (though viral gastroenteritis remains most likely regardless) 6

Past Medical History

• No chronic medical conditions that would predispose to metabolic causes (diabetes, renal disease, adrenal insufficiency) 4
• No history of cyclic vomiting syndrome 4

Most Likely Diagnosis

• Viral gastroenteritis is the most common cause of acute vomiting in this age group, though systematic exclusion of serious bacterial infections and surgical emergencies must occur before settling on this diagnosis 6