What is rhinitis medicamentosa in an adult with a history of chronic rhinosinusitis?

What is Rhinitis Medicamentosa?

Rhinitis medicamentosa is a condition of paradoxical nasal congestion caused by prolonged use of topical nasal decongestants (such as oxymetazoline or xylometazoline), characterized by rebound swelling, nasal hyperreactivity, and tolerance that worsens with continued use. 1

Pathophysiology and Mechanism

The condition develops through several interconnected mechanisms:

• Rebound vasodilatation occurs when the vasoconstrictive effects of α-adrenergic agonists wear off, leading to paradoxical mucosal swelling that exceeds baseline congestion 1, 2
• Tachyphylaxis develops as nasal mucosa becomes refractory to the decongestant effects, requiring progressively higher doses and more frequent administration 1, 3
• Reduced mucociliary clearance results from loss of ciliated epithelial cells with chronic exposure 3, 2
• Parasympathetic rebound may be triggered as a compensatory response to prolonged α-adrenergic stimulation 1
• Benzalkonium chloride (BKC), the preservative in most nasal sprays, independently causes mucosal swelling after 30 days of use and augments the pathologic effects of the vasoconstrictor itself 2, 4, 5

Timeline and Clinical Presentation

The onset is surprisingly rapid:

• Rebound congestion can begin as early as 3-4 days of continuous topical decongestant use, though some patients may not develop symptoms until 4-6 weeks 6, 3, 2
• Patients experience worsening nasal congestion between doses, creating a vicious cycle of increasing frequency and dosage 3, 2, 4
• The condition manifests as persistent bilateral nasal obstruction despite continued decongestant use 1
• In severe cases, nasal mucosal damage and rarely nasal septal perforation can occur 3, 2

Diagnostic Considerations in Chronic Rhinosinusitis Patients

For adults with chronic rhinosinusitis, diagnosis requires careful history-taking:

• Obtain detailed medication history including both legal nasal decongestant use (oxymetazoline, xylometazoline) and illegal nasal drug use (cocaine, which produces a similar rhinitis medicamentosa-like state) 1, 3
• Patients are often unaware they have developed the condition and may not volunteer information about over-the-counter nasal spray use without direct questioning 4
• The diagnosis is primarily clinical, based on history of prolonged topical decongestant use combined with worsening nasal congestion 1
• Physical examination may show mucosal edema and erythema, but findings are nonspecific 2, 4

Important Clinical Pitfalls

Several caveats warrant attention:

• Other medications can cause nasal congestion including β-blockers, ACE inhibitors, phosphodiesterase-5 inhibitors, and α-receptor antagonists, but these do not cause the rebound phenomenon characteristic of rhinitis medicamentosa 1
• The condition is distinct from the underlying nasal disorder (such as chronic rhinosinusitis or allergic rhinitis) that may have prompted initial decongestant use 2, 4
• Patients who successfully discontinue topical decongestants remain at high risk for rapid recurrence if they resume use, even for just a few days 2, 4
• The pathophysiology is not fully understood, and the relative contributions of the vasoconstrictor versus the preservative BKC continue to be debated 2, 4, 5