What is the differential diagnosis for epigastric pain and the recommended initial evaluation?

Differential Diagnosis and Initial Evaluation of Epigastric Pain

Life-Threatening Causes (Rule Out Immediately)

Myocardial infarction must be excluded first in all patients with epigastric pain, as it presents atypically with epigastric symptoms in 10-20% of cases, particularly in women, diabetics, and elderly patients, with mortality rates reaching 10-20% if missed. 1, 2, 3

• Obtain an ECG within 10 minutes of presentation and measure serial cardiac troponins at 0 and 6 hours—never rely on a single troponin measurement 1, 2, 3
• Chest tenderness on palpation or pain with inspiration markedly reduces the probability of acute coronary syndrome 1
• Diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3 gallop, or new mitral regurgitation murmur suggest myocardial infarction 1

Perforated peptic ulcer presents with sudden, severe epigastric pain that becomes generalized, accompanied by fever, abdominal rigidity, and absent bowel sounds, with mortality reaching 30% if treatment is delayed. 1, 2, 3

• CT with IV contrast demonstrates extraluminal gas in 97% of cases, fluid or fat stranding in 89%, ascites in 89%, and focal wall defect in 84% 1, 2
• Requires emergent surgical consultation for laparoscopic or open repair 2

Acute aortic dissection causes sudden, severe epigastric pain radiating to the back or shoulders and requires emergent CT angiography. 1, 2

• Look for connective tissue disorders (Marfan syndrome), extremity pulse differential (present in 30% of patients), and widened mediastinum on chest x-ray 1
• Severe pain with abrupt onset plus pulse differential plus widened mediastinum indicates >80% probability of dissection 1

Acute pancreatitis characteristically presents with epigastric pain radiating to the back, diagnosed by serum amylase ≥4x normal or lipase ≥2x normal with 80-90% sensitivity and specificity. 2, 3

• Can progress to necrotizing pancreatitis with multiorgan failure 2

Mesenteric ischemia causes severe epigastric pain with pain out of proportion to examination findings, requiring CT angiography for diagnosis. 2

• Leukocytosis and elevated serum lactate indicate poor tissue perfusion and correlate with bowel ischemia 2

Esophageal rupture produces chest pain accompanied by a painful, tympanic abdomen and represents a potentially life-threatening gastrointestinal emergency. 1

Common Gastrointestinal Causes

Peptic ulcer disease has an incidence of 0.1-0.3%, with complications occurring in 2-10% of cases. 1, 2, 3

• CT findings include gastric or duodenal wall thickening due to submucosal edema, mucosal hyperenhancement, fat stranding, focal outpouching from ulcerations, or focal interruption of mucosal enhancement 1
• Active bleeding appears as hyperdense blood products or active contrast extravasation 1
• Wall defect and/or ulcer shows a positive likelihood ratio for gastroduodenal perforation of 36.83, while wall thickening shows a positive likelihood ratio of 10.52 1

Gastroesophageal reflux disease (GERD) affects 42% of Americans monthly and 7% daily, presenting with heartburn, regurgitation, and epigastric pain. 1, 2, 3

• Distal esophageal wall thickening (≥5 mm) on CT has 56% sensitivity and 88% specificity for reflux esophagitis 1, 4
• Presence of air in the esophagus, especially the middle and lower parts, suggests GERD 1

Gastric cancer may present with an ulcer associated with nodularity of adjacent mucosa, mass effect, or irregular radiating folds, and is now the most common cause of gastric outlet obstruction in adults with 5-year survival rate of 32%. 2, 3

• Alarm features include weight loss, dysphagia, hematemesis, persistent vomiting, and anemia 2

Initial Evaluation Algorithm

Check vital signs immediately for tachycardia ≥110 bpm, fever ≥38°C, or hypotension, which predict perforation, anastomotic leak, or sepsis. 2, 3, 4

Perform focused cardiovascular examination to identify complications and life-threatening causes including aortic dissection, pulmonary embolism, or esophageal rupture. 1

• Examine for peritoneal signs (rigidity, rebound tenderness, absent bowel sounds) indicating perforation 2, 4
• Epigastric tenderness suggests esophagitis, peptic ulcer disease, or gallbladder disease 1
• Tenderness of costochondral joints indicates musculoskeletal cause 1

Obtain ECG within 10 minutes of presentation to exclude myocardial ischemia. 1, 2, 3, 4

Order initial laboratory tests including:

• Cardiac troponins at 0 and 6 hours (serial measurements mandatory) 1, 2, 3, 4
• Complete blood count, C-reactive protein, serum lactate levels 2, 4
• Serum amylase or lipase to exclude acute pancreatitis 2, 3, 4
• Liver and renal function tests 2, 4

CT abdomen and pelvis with IV contrast is the gold standard when diagnosis is unclear, identifying pancreatitis, perforation, and vascular emergencies. 1, 2, 3, 4

• Use neutral oral contrast (water or dilute barium) when gastric disease is suspected to delineate intraluminal space 1
• CT angiography if mesenteric ischemia or aortic dissection suspected 2, 4

Upper endoscopy is definitive for peptic ulcer disease, gastritis, and esophagitis when patient is stable. 1, 2, 3

Empiric Management While Awaiting Diagnosis

Maintain NPO status until surgical emergency is excluded. 2

Establish IV access and provide fluid resuscitation if hemodynamically unstable. 2

Start high-dose PPI therapy (omeprazole 20-40 mg once daily) for suspected acid-related pathology, with healing rates of 80-90% for duodenal ulcers and 70-80% for gastric ulcers. 2, 3, 4

• Avoid NSAIDs as they worsen peptic ulcer disease and bleeding risk 2

Initiate broad-spectrum antibiotics if septic shock develops. 2

Critical Pitfalls to Avoid

Never dismiss cardiac causes in patients with "atypical" epigastric pain, regardless of age—the absence of chest pain does not exclude cardiac disease. 1, 2, 3, 4

Do not delay imaging in patients with peritoneal signs, as perforated ulcer mortality increases significantly with delayed diagnosis. 2, 3

Never rely on single troponin measurement; serial measurements at least 6 hours apart are required to exclude NSTEMI. 2, 3, 4

Do not assume GERD without excluding life-threatening causes first, even in patients with known reflux disease. 2

Persistent vomiting with epigastric pain excludes functional dyspepsia and mandates investigation for structural disease such as peptic ulcer or acute coronary syndrome. 2

Do not delay endoscopy in patients with alarm features (persistent vomiting, weight loss, anemia, dysphagia), as this leads to poor outcomes. 2