What are the possible diagnoses and next steps for a 31-year-old female with chronic Gastroesophageal Reflux Disease (GERD), presenting with sharp, pleuritic pain around the right shoulder blade, fever, and a history of vomiting, after taking Gaviscon (sodium alginate) with minimal relief?

Differential Diagnosis and Immediate Next Steps

This patient requires urgent evaluation for biliary colic or acute cholecystitis, not GERD exacerbation, and should undergo right upper quadrant ultrasound immediately. 1

Critical Clinical Reasoning

The presentation is highly atypical for isolated GERD despite the patient's chronic history:

• Sharp, pleuritic right shoulder blade pain aggravated by inhalation is classic for referred pain from gallbladder pathology via phrenic nerve irritation, not typical GERD 1
• Radiation to upper right chest follows the pattern of biliary colic, not esophageal reflux 1
• Fever with vomiting suggests acute inflammation (cholecystitis) rather than uncomplicated GERD 2
• Minimal relief from Gaviscon argues against acid-mediated symptoms 2
• Pain NOT aggravated by joint movement helps exclude musculoskeletal causes 1

Primary Differential Diagnoses

1. Acute Cholecystitis/Biliary Colic (Most Likely)

• Right shoulder blade pain (Boas sign) with right upper chest radiation is pathognomonic 1
• Fever and vomiting support acute inflammation 2
• Young female fits demographic risk profile 1

2. Pleurisy or Pneumonia

• Pleuritic chest pain aggravated by inhalation 2
• Fever present 2
• However, right shoulder blade as primary pain location is less typical 1

3. GERD Exacerbation (Less Likely Given Presentation)

• Chronic history present 2
• However, pleuritic quality, fever, and anatomic distribution are atypical 2
• Negative H. pylori makes peptic ulcer disease less likely 2

4. Pancreatitis

• Can present with epigastric pain radiating to back 1
• However, right shoulder blade as primary location is unusual 1

Immediate Diagnostic Workup

First-Line Testing (Urgent)

• Right upper quadrant ultrasound to evaluate for cholelithiasis, gallbladder wall thickening, pericholecystic fluid 1
• Complete blood count to assess for leukocytosis suggesting infection 2
• Comprehensive metabolic panel including liver function tests (AST, ALT, alkaline phosphatase, bilirubin) 1
• Lipase to exclude pancreatitis 1

Second-Line Testing (If Initial Workup Negative)

• Chest X-ray to evaluate for pneumonia or pleural effusion given pleuritic component 2
• Hepatobiliary iminodiacetic acid (HIDA) scan if ultrasound is equivocal but clinical suspicion for acalculous cholecystitis remains high 1

Management Algorithm

If Biliary Pathology Confirmed:

• Surgical consultation for potential cholecystectomy 1
• NPO status with IV hydration 1
• Analgesia and antiemetics 1
• Antibiotics if acute cholecystitis confirmed (e.g., ceftriaxone plus metronidazole) 1

If Pulmonary Pathology Confirmed:

• Antibiotics for community-acquired pneumonia if indicated 2
• Supportive care for viral pleurisy 2

If All Testing Negative:

Only then consider GERD-related evaluation:

• Upper endoscopy to evaluate for erosive esophagitis, Barrett's esophagus, or alternative diagnoses 2, 1
• 96-hour wireless pH monitoring off PPI if endoscopy is normal to objectively confirm GERD 2, 1
• Twice-daily PPI therapy (e.g., omeprazole 20 mg twice daily) for 8-12 weeks if GERD confirmed 2

Critical Pitfalls to Avoid

• Do not attribute fever to GERD—uncomplicated GERD does not cause fever and this should prompt evaluation for infection or inflammation 2
• Do not continue empiric PPI therapy without objective testing when the presentation is atypical, as 50-60% of patients with suspected GERD symptoms will not have pathologic reflux 2, 1
• Do not miss surgical emergencies by prematurely anchoring on chronic GERD diagnosis—new symptom patterns require fresh evaluation 1
• Cardiac evaluation must be completed before attributing any chest pain to GERD, though this patient's young age and pleuritic quality make ischemia less likely 2, 1

Why This Is Not Typical GERD

The 2023 AGA guidelines emphasize that extraesophageal or atypical presentations without concurrent typical reflux symptoms (heartburn, regurgitation) should prompt early objective testing rather than empiric PPI trials 2. This patient's presentation lacks typical GERD features and has multiple red flags for alternative diagnoses 2.