Aspirin-exacerbated respiratory disease

Regular strength enteric coated aspirin tablets

Aspirin-Exacerbated Respiratory Disease (AERD), also known as Samter's Triad or aspirin-induced asthma, is a chronic medical condition affecting the respiratory system and characterized by three key features: asthma, sinus disease with recurrent nasal polyps, and a sensitivity to aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) that inhibit the cyclooxygenase-1 (COX-1) enzyme. This condition represents a complex interaction between various genetic, environmental, and immunological factors, leading to a unique and challenging clinical syndrome.

Overview

AERD is a distinct clinical syndrome that affects approximately 0.3% to 0.9% of the general population and up to 7% of asthmatic patients. It typically manifests in adulthood, with patients often presenting in their 30s and 40s. The pathophysiology of AERD involves an abnormal increase in leukotriene production, a group of inflammatory mediators, which plays a central role in the disease's expression. This overproduction is triggered by the ingestion of aspirin or other NSAIDs, leading to acute and sometimes severe respiratory reactions including bronchoconstriction, nasal congestion, and rhinosinusitis.

Symptoms

The clinical presentation of AERD includes:

• Asthma: Often severe and difficult to control with standard treatments.
• Nasal polyps: Recurrent sinus polyps that are resistant to treatment and often require surgical removal.
• Sensitivity to aspirin and NSAIDs: Ingestion of these medications can lead to severe respiratory reactions, including rhinitis, bronchospasm, and systemic reactions such as urticaria, angioedema, and anaphylaxis.

Diagnosis

Diagnosis of AERD is primarily clinical, based on the patient's history of the triad symptoms. However, aspirin challenge testing, either orally, nasally, or by inhalation, is considered the gold standard for confirming the diagnosis. Additional diagnostic tools include measurement of urinary leukotriene E4 levels and endoscopic evaluation of the sinuses to assess for nasal polyps.

Treatment

Management of AERD involves a combination of strategies aimed at controlling asthma symptoms, preventing the growth of nasal polyps, and avoiding triggers:

• Asthma management typically includes the use of inhaled corticosteroids and leukotriene receptor antagonists.
• Surgical removal of nasal polyps may be necessary for patients with significant nasal obstruction or recurrent sinus infections.
• Aspirin desensitization is a unique treatment for AERD that can reduce sensitivity to aspirin and NSAIDs, improve smell, reduce nasal congestion, and decrease the need for sinus surgery. Following desensitization, patients must continue to take aspirin daily to maintain desensitization status.
• Avoidance of aspirin and other NSAIDs is crucial for patients who have not undergone desensitization.

Epidemiology

AERD is more common in adults and is rarely diagnosed in children. There is no clear gender predilection. The exact prevalence of AERD is difficult to determine due to underdiagnosis and the variability of disease expression among individuals.

Conclusion

AERD is a complex condition that requires a multidisciplinary approach for management, involving allergists, pulmonologists, and otolaryngologists. Early recognition and appropriate treatment are essential for improving quality of life and preventing complications associated with this disease.