Can pneumonia or Covid-19 (Coronavirus disease 2019) cause referred pain to the abdomen?

Can Pneumonia or COVID-19 Cause Referred Pain to the Abdomen?

Yes, both pneumonia and COVID-19 can cause referred pain to the abdomen, which can sometimes mimic acute abdominal conditions requiring surgical intervention. 1, 2

COVID-19 and Abdominal Pain

Pathophysiology and Presentation

• COVID-19 can present with abdominal pain through several mechanisms:
  • Direct viral infection of gastrointestinal tract cells expressing ACE2 receptors 1
  • Referred pain from lower lobe pneumonia affecting the diaphragm 1, 3
  • Systemic inflammatory response affecting multiple organs 1
• Abdominal pain in COVID-19 patients may be severe enough to mimic surgical conditions like peritonitis or appendicitis 2, 4

Clinical Evidence

• COVID-19 patients may present with acute abdominal pain even without respiratory symptoms, despite having typical lung lesions on imaging 3
• Studies have documented that 2.9-6.8% of COVID-19 patients present with abdominal pain 1
• Severe cases of COVID-19 have higher rates of abdominal pain (6.8%) compared to non-severe cases (3.2%) 1
• COVID-19 can cause specific abdominal complications including:
  • Acute pancreatitis 5, 6
  • Appendicitis-like presentations 4
  • Secondary peritonitis-like features 2

Diagnostic Considerations

Imaging Findings

• CT scans of patients presenting with abdominal pain should include evaluation of the lung bases, as COVID-19 pneumonia may be incidentally discovered 3
• Chest CT is the most accurate radiological tool to confirm COVID-19 diagnosis in uncertain cases 1
• Lung ultrasound can be used as a screening tool in patients with abdominal pain to evaluate for possible COVID-19 pneumonia 1

Laboratory Findings

• Patients with COVID-19 presenting with abdominal pain often have:
  • Elevated inflammatory markers (C-reactive protein) 3
  • Abnormal liver function tests 1, 7
  • Leukopenia and lymphopenia 1

Management Approach

Evaluation Algorithm

1. Consider COVID-19 in any patient presenting with acute abdominal pain during the pandemic, even without respiratory symptoms 1, 3
2. Perform COVID-19 testing with RT-PCR nasopharyngeal swab 1
3. Include chest imaging (CT, X-ray, or lung ultrasound) in the evaluation of unexplained abdominal pain 1, 3
4. Assess for elevated liver enzymes and inflammatory markers 1, 7
5. Consider non-operative management when appropriate for conditions like uncomplicated appendicitis in COVID-19 patients 1

Surgical Considerations

• Surgery should not be delayed for true surgical emergencies while waiting for COVID-19 test results 1
• Conservative management should be maximized when possible in COVID-19 patients with abdominal conditions 1
• Senior clinicians should be involved early in decision-making for suspected COVID-19 patients with abdominal pain 1

Common Pitfalls and Caveats

• Mistaking COVID-19-related abdominal pain for a primary surgical condition may lead to unnecessary surgical interventions 2, 4
• Failure to consider COVID-19 in patients with abdominal pain can delay appropriate isolation measures and increase transmission risk to healthcare workers 1, 3
• Gastrointestinal symptoms may be the only initial manifestation of COVID-19 in some patients 1
• COVID-19 should be considered when assessing patients with diarrhea, abdominal pain, and/or fever, even without respiratory symptoms 1