Most Likely Diagnosis: Peptic Ulcer Disease with Gastritis
The most likely diagnosis is peptic ulcer disease (PUD) with gastritis, given the combination of epigastric pain, abdominal cramping, and a single fever episode without the typical gastrointestinal symptoms of nausea, vomiting, or diarrhea. 1, 2
Clinical Reasoning
Why PUD/Gastritis is Most Likely
Epigastric pain is the hallmark symptom of peptic ulcer disease and gastritis, which have an incidence of 0.1-0.3% but remain important diagnoses due to potential complications occurring in 2-10% of cases 1, 2, 3
The absence of nausea, vomiting, and diarrhea makes gastroenteritis unlikely, as viral gastroenteritis typically presents with the triad of diarrhea, nausea/vomiting, and abdominal pain 4, 5, 6
A single fever episode can occur with PUD complications, particularly when there is mucosal inflammation or early perforation, though fever is not the dominant feature 2, 3
Abdominal cramping fits the pattern of peptic ulcer disease, which presents with epigastric pain that may have a cramping quality 1, 2
Critical Differential Diagnoses to Exclude First
Life-threatening conditions must be ruled out immediately:
Perforated peptic ulcer presents with sudden severe epigastric pain, fever, and abdominal rigidity, with mortality reaching 30% if treatment is delayed 2, 3, 7
Myocardial infarction can present atypically with epigastric pain as the primary manifestation, especially in women, diabetics, and elderly patients, with mortality rates of 10-20% if missed 3, 7
Acute pancreatitis characteristically presents with epigastric pain radiating to the back, though the absence of back pain and vomiting makes this less likely 1, 3, 7
Why Other Diagnoses Are Less Likely
Gastroenteritis is unlikely because viral gastroenteritis causes non-bloody diarrhea, nausea, and vomiting as core features, which are absent in this patient 4, 5, 6
GERD/esophagitis typically presents with heartburn and regurgitation, which are not mentioned here, though these conditions affect 42% of Americans monthly 1, 3, 7
Acute cholecystitis would typically present with right upper quadrant pain rather than epigastric pain, though it remains in the differential for nonlocalized abdominal pain with fever 1
Immediate Diagnostic Approach
Check for peritoneal signs immediately:
Assess for abdominal rigidity, rebound tenderness, and guarding, as these indicate potential perforation requiring immediate surgical consultation 2, 3
Measure vital signs looking for tachycardia ≥110 bpm, hypotension, or persistent fever ≥38°C, which predict complications with high specificity 7
Order initial laboratory tests:
Complete blood count to assess for anemia (suggesting chronic bleeding) or leukocytosis (suggesting perforation or infection) 7
Serum amylase or lipase (≥4x normal for amylase or ≥2x normal for lipase) to exclude pancreatitis with 80-90% sensitivity and specificity 3, 7
Cardiac troponins at 0 and 6 hours to exclude myocardial infarction—do not rely on a single measurement 3, 7
Imaging strategy:
CT abdomen and pelvis with IV contrast is the gold standard when diagnosis is unclear, identifying perforation (extraluminal gas in 97% of cases), pancreatitis, and vascular emergencies 3, 7
Upper endoscopy is definitive for PUD and gastritis when the patient is stable and should be performed to confirm diagnosis and assess for H. pylori 1, 2, 3
Initial Management
Start empiric therapy while awaiting diagnostic confirmation:
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 3, 7
Maintain NPO status until surgical emergency is excluded, particularly if peritoneal signs are present 7
Avoid NSAIDs as they worsen peptic ulcer disease and increase bleeding risk 7
Critical Pitfalls to Avoid
Never dismiss cardiac causes in patients with epigastric pain regardless of age or presentation—obtain ECG within 10 minutes and serial troponins 3, 7
Do not delay imaging in patients with peritoneal signs, as perforated ulcer mortality increases significantly with delayed diagnosis 2, 3
Fever with epigastric pain raises concern for perforation, which presents with sudden severe pain, fever, and abdominal rigidity and carries mortality rates up to 30% 2, 3
If peritoneal signs develop, immediate surgical consultation is mandatory 2