What is the best course of treatment for a patient presenting with a sore throat, nausea, vomiting, and mild tenderness to the right lower abdomen?

Diagnostic Workup and Management for Suspected Appendicitis

Obtain a contrast-enhanced CT scan of the abdomen and pelvis immediately, as this patient's presentation of sore throat with nausea, vomiting, and right lower quadrant tenderness is classic for acute appendicitis, which requires urgent surgical evaluation. 1, 2

Clinical Reasoning

The combination of nausea, vomiting, and right lower quadrant pain represents the classic triad of acute appendicitis, which typically begins with periumbilical or epigastric pain that migrates to the RLQ, accompanied by anorexia, nausea, and vomiting. 2 The sore throat is likely a coincidental viral pharyngitis or referred pain, and should not distract from the more concerning abdominal findings. 3

Key Physical Examination Findings to Assess

• Test for psoas sign (pain with hip extension or flexion), which suggests appendicitis or retroperitoneal pathology and may explain any back pain component. 2, 4
• Assess for peritoneal signs including rebound tenderness and guarding in the right lower quadrant. 5
• Elicit Murphy's sign to exclude cholecystitis, though the pain location makes this less likely. 1

Diagnostic Imaging Strategy

CT abdomen and pelvis with IV contrast (without enteral contrast) is the definitive first-line imaging modality, achieving sensitivities of 85.7-100% and specificities of 94.8-100% for identifying appendicitis. 1, 2, 6 This approach:

• Reduces negative appendectomy rates from historical rates of 14.7-25% without imaging to approximately 1.7-7.7% with CT. 1, 6
• Avoids delays associated with oral contrast administration, which increases time to diagnosis and potentially increases perforation risk without improving diagnostic accuracy. 6, 4
• Identifies alternative diagnoses including psoas abscess, mesenteric adenitis, diverticulitis, infectious colitis, and neutropenic enterocolitis. 1, 4

Alternative Imaging Considerations

Ultrasound could be considered as a first-line modality with average sensitivity of 87.1% and specificity of 89.2%, but CT remains superior for definitive diagnosis, particularly in obese patients where ultrasound has higher false diagnosis rates (46.2% vs 38.5%). 6, 5

Laboratory Testing

Order the following labs immediately:

• C-reactive protein and complete blood count, as CRP levels are significantly higher in appendicitis versus other etiologies, and normal inflammatory markers have 100% negative predictive value for excluding appendicitis. 2, 4
• Basic metabolic panel to assess for dehydration and electrolyte abnormalities from vomiting. 4
• Urinalysis to exclude urinary tract infection or nephrolithiasis. 5, 3

Management Based on Imaging Results

If Appendicitis is Confirmed

Proceed directly to appendectomy as standard treatment. 2 For uncomplicated appendicitis in immunocompetent patients:

• Perform early laparoscopic or open appendectomy within 7-10 days of symptom onset. 1
• Administer one-shot antibiotic prophylaxis if early intervention. 1
• No post-operative antibiotics are needed if source control is adequate. 1

If Perforated Appendicitis with Abscess

Consider percutaneous drainage followed by delayed surgery, with antibiotic therapy for 4 days in immunocompetent patients or up to 7 days in immunocompromised or critically ill patients if source control is adequate. 1, 2

If CT is Negative but Clinical Suspicion Remains High

Diagnostic laparoscopy is recommended, which has both diagnostic and therapeutic value. 2, 6

Symptomatic Management While Awaiting Definitive Treatment

• Provide IV fluid resuscitation for dehydration from vomiting. 2
• Administer antiemetics such as dopamine antagonists (metoclopramide or prochlorperazine) or serotonin antagonists for nausea and vomiting control. 2
• Keep patient NPO in preparation for potential surgery. 1

Critical Pitfalls to Avoid

Do not delay imaging for oral contrast administration, as this increases time to diagnosis without improving accuracy. 6, 4 Do not rely on clinical scoring systems alone, as they may not accurately exclude appendicitis, particularly with atypical presentations. 4 Do not dismiss the abdominal findings due to the sore throat, as acute nausea and vomiting with abdominal pain warrants immediate evaluation for surgical pathology rather than assuming viral gastroenteritis. 3, 7