Likely Diagnosis: Viral Gastroenteritis with Pharyngeal Irritation from Vomiting
This patient most likely has viral gastroenteritis causing morning vomiting, with the sore throat being secondary to gastric acid irritation from repeated vomiting rather than primary pharyngitis. The normal throat examination, absence of respiratory symptoms (no mucus, clear lungs), and timing of symptoms (morning vomiting) point away from primary respiratory infection and toward a gastrointestinal etiology 1, 2.
Clinical Reasoning
Why This Is NOT Primary Pharyngitis
The physical examination findings argue strongly against bacterial or viral pharyngitis as the primary problem:
- Normal throat appearance - True pharyngitis (viral or bacterial) typically shows pharyngeal erythema, with or without exudates 3
- No respiratory symptoms - Absence of cough, nasal congestion, or mucus production makes viral upper respiratory infection unlikely 4, 5
- Normal ears - Rules out associated otitis media that can accompany respiratory infections 3
- Clear lung sounds - Excludes lower respiratory tract involvement 3
Why Viral Gastroenteritis Is Most Likely
The symptom pattern fits viral gastroenteritis:
- Morning vomiting is characteristic of gastroenteritis, particularly when the stomach is empty 1, 6
- Sore throat with normal throat exam suggests mechanical irritation from gastric acid reflux during vomiting rather than infectious pharyngitis 1
- Appears ill - Viral gastroenteritis causes systemic symptoms including malaise and dehydration 6, 2
- Viruses are the most common cause of gastroenteritis worldwide, including rotavirus, caliciviruses (norovirus), astrovirus, and adenovirus 2
Diagnostic Approach
Key Questions to Ask
- Diarrhea? - Most viral gastroenteritis presents with both vomiting and diarrhea 1, 2
- Fever? - Common in viral gastroenteritis 6
- Sick contacts or food exposure? - Caliciviruses cause institutional epidemics and food-borne outbreaks 1
- Timing of vomiting - Morning predominance suggests gastric irritation 1
- Abdominal pain? - Expected with gastroenteritis 6
What Testing Is NOT Needed
- No throat culture or rapid strep test - The normal throat examination and absence of bacterial pharyngitis features (no exudates, no tender cervical adenopathy, no fever with tonsillar swelling) make Group A Streptococcus extremely unlikely 3
- No chest X-ray - Clear lung sounds and absence of dyspnea, tachypnea, or focal chest findings rule out pneumonia 5
- No antibiotics indicated - This is a viral illness 6, 2
Management
Primary Treatment: Rehydration
The primary goal is preventing and treating dehydration, which is the main cause of morbidity and mortality in viral gastroenteritis 6:
- Oral rehydration solution is first-line treatment 6
- Small, frequent sips if vomiting is ongoing 6
- IV rehydration only if unable to tolerate oral fluids or signs of severe dehydration 6
Symptomatic Relief
- Antiemetics may be considered for severe vomiting, though evidence is limited 6
- Analgesics (acetaminophen or NSAIDs) for throat discomfort from acid irritation 5
- Avoid aspirin in children due to Reye syndrome risk 7
Nutritional Management
- Resume normal diet as tolerated once vomiting subsides 6
- Avoid prolonged fasting which can worsen nutritional status 6
Red Flags Requiring Immediate Evaluation
Return immediately if:
- Signs of severe dehydration - decreased urination, dizziness, dry mucous membranes, tachycardia 6
- Bloody diarrhea or vomit - suggests bacterial infection or other serious pathology 1
- Severe abdominal pain - may indicate surgical abdomen 1
- High fever >4 days - suggests bacterial superinfection 5
- Inability to keep down any fluids - requires IV rehydration 6
Common Pitfall to Avoid
Do not prescribe antibiotics for presumed "strep throat" based solely on the complaint of sore throat when the physical examination is normal. The sore throat here is secondary to vomiting-induced irritation, not primary pharyngitis 3, 5. Unnecessary antibiotics contribute to resistance, cause adverse effects, and provide no benefit in viral illness 3.