What are the causes of pleuradynia?

Causes of Pleuradynia

Pleuradynia is primarily caused by enterovirus infections, particularly Coxsackievirus group B, which accounts for the majority of cases. 1

Primary Cause: Viral Infections

Enterovirus Infections

• Coxsackievirus B is the predominant causative agent 1, 2
  • Particularly Coxsackievirus B3 (CB3) has been identified in up to 60% of cases in some outbreaks 2
  • Other serotypes including B1, B2, B4, B5, and B6 have also been implicated 3
• Pathophysiology: The virus causes inflammation of the pleura and intercostal muscles, leading to the characteristic sharp, localized pain 2

Clinical Features of Pleuradynia

• Sharp, localized pain over the chest or upper abdomen that is typically pleuritic (worsens with breathing) 2
• Sudden onset of symptoms
• Self-limiting nature, typically resolving within days to weeks
• May be accompanied by:
  • Fever
  • Headache
  • Abdominal pain
  • Upper respiratory symptoms 2

Diagnostic Findings

Laboratory Findings

• Immunoglobulin M (IgM) antibodies to Coxsackieviruses can be detected in approximately 27% of patients with pleuradynia 3
• Viral isolation from throat swabs or stool specimens may yield the causative virus 2, 4
• Creatinine kinase levels are typically normal or only mildly elevated 2

Radiological Findings

• Chest radiographs may show:
  • Pulmonary infiltrates in some cases
  • Pleural effusions (small to moderate) 2
  • Normal findings in many cases

Complications and Associated Conditions

Pleuradynia can be associated with other manifestations of enterovirus infections:

• Myocarditis/Pericarditis: Cardiac involvement can occur concurrently 5, 3
• Aseptic meningitis: Neurological manifestations may develop 5
• Herpangina: Vesicular pharyngeal lesions 4
• Post-viral fatigue syndrome: Some patients may develop prolonged fatigue following the acute illness 6

Differential Diagnosis

When evaluating pleuradynia, it's important to distinguish it from:

1. Pleural infection/empyema: Unlike bacterial pleural infections, pleuradynia is viral in origin and typically doesn't require drainage 1
2. Malignant pleural effusions: These are typically associated with underlying malignancy rather than viral infection 1
3. Precordial catch syndrome: A benign condition causing sharp, brief chest pain that intensifies with inspiration but is not associated with viral infection 7
4. Pneumonia with parapneumonic effusion: Bacterial in origin with different treatment approach 1

Epidemiological Considerations

• Pleuradynia often occurs in epidemic outbreaks, hence the term "epidemic pleuradynia" 2, 4
• More common in children and young adults 5
• Can affect multiple individuals in the same community during outbreaks
• Seasonal variation with higher incidence during summer and fall months

Management Approach

Management is primarily supportive as the condition is typically self-limiting:

• Analgesics for pain control
• Rest during the acute phase
• Monitoring for potential complications like myocarditis
• Antiviral therapy is generally not indicated or effective

Important Clinical Pitfalls

• Misdiagnosing pleuradynia as bacterial pleural infection can lead to unnecessary invasive procedures
• Failing to recognize potential cardiac complications (myocarditis/pericarditis)
• Attributing symptoms to psychogenic causes, leading to delayed diagnosis 6
• Not considering pleuradynia in patients with acute chest pain, especially during known enterovirus outbreaks

In summary, pleuradynia is primarily caused by Coxsackievirus group B infections, particularly type B3, resulting in inflammation of the pleura and surrounding tissues. The diagnosis should be considered in patients presenting with acute pleuritic chest pain, especially during enterovirus seasons or outbreaks.