Why are nasal polyps a contraindication to Aspirin (acetylsalicylic acid) use?

Nasal Polyps as a Contraindication to Aspirin Use: The AERD Connection

Nasal polyps are a contraindication to aspirin use because they may indicate Aspirin-Exacerbated Respiratory Disease (AERD), a condition that can trigger severe and potentially life-threatening respiratory reactions including bronchospasm, rhinorrhea, and asthma attacks upon exposure to aspirin or other COX-1 inhibiting NSAIDs. 1

Understanding AERD and Its Relationship to Nasal Polyps

AERD (also called N-ERD or Samter's triad) is characterized by:

1. Chronic rhinosinusitis with nasal polyps
2. Asthma
3. Respiratory reactions to aspirin and NSAIDs that inhibit COX-1 enzyme

The presence of nasal polyps in a patient, particularly when accompanied by asthma, should raise suspicion for potential AERD. Approximately one-third of patients with asthma and nasal polyposis have AERD, making this a significant clinical concern. 1

Pathophysiology

The mechanism behind AERD involves dysregulated arachidonic acid metabolism:

• When patients with AERD take aspirin or other COX-1 inhibitors, there is:
  • Decreased prostaglandin E2 production
  • Increased cysteinyl leukotrienes
  • Increased tryptase
  • Diminished prostaglandin D2
  • Continued 5-lipoxygenase activity 1

This altered eicosanoid metabolism leads to the characteristic respiratory symptoms when these patients are exposed to aspirin or other NSAIDs.

Clinical Presentation of Aspirin Reaction in AERD Patients

When patients with nasal polyps and underlying AERD take aspirin, they may experience:

• Upper respiratory symptoms: nasal blockage, rhinorrhea, nasal/ocular itching
• Lower respiratory symptoms: bronchospasm, wheezing, chest tightness
• Systemic symptoms: flushing, hypotension (in severe cases)

These reactions are typically sudden and often severe, occurring within 30 minutes to 3 hours after aspirin ingestion. 1

Diagnosis

The diagnosis of AERD is usually established by:

1. History of respiratory symptoms after NSAID ingestion
2. Presence of chronic rhinosinusitis with nasal polyps
3. Asthma

In cases of diagnostic uncertainty, an aspirin challenge may be performed in a controlled setting. However, in patients with a clear history of multiple reactions to structurally dissimilar NSAIDs or a severe reaction requiring hospitalization, further diagnostic testing with aspirin challenge is unnecessary and potentially dangerous. 1

Management Options for Patients with Nasal Polyps

For patients with nasal polyps who need pain relief:

• Selective COX-2 inhibitors (e.g., celecoxib) can generally be used safely as they rarely cause reactions in AERD patients 1
• Acetaminophen at lower doses may be tolerated by some patients
• For patients who absolutely require aspirin therapy (e.g., for cardiovascular protection), aspirin desensitization followed by daily aspirin therapy can be considered under specialist supervision 1

Aspirin Desensitization

For patients with confirmed AERD who would benefit from aspirin therapy:

• Aspirin desensitization followed by daily aspirin treatment (typically 300-650 mg twice daily) has shown significant benefits:
  • Reduction in sinus infections
  • Decreased need for systemic corticosteroids
  • Improvement in sense of smell
  • Reduction in nasal polyp recurrence 1, 2

However, this procedure must be performed under careful medical supervision due to the risk of severe reactions during the desensitization process.

Important Clinical Considerations

• Always ask patients with nasal polyps about reactions to aspirin and other NSAIDs 1
• Consider AERD in any patient with the triad of asthma, nasal polyps, and NSAID sensitivity
• Recognize that AERD typically develops after an upper respiratory infection, with perennial rhinitis followed by nasal polyposis and progression to asthma 1
• Be aware that despite avoidance of aspirin and cross-reacting drugs, these patients typically experience refractory rhinosinusitis and asthma 1

By recognizing the association between nasal polyps and potential aspirin sensitivity, clinicians can prevent potentially serious adverse reactions and provide appropriate alternative treatment options for these patients.