What is the role of antihistamines (anti-allergic medications) in the management of viral rhinosinusitis?

Role of Antihistamines in Viral Rhinosinusitis

Antihistamines are not recommended for the treatment of viral rhinosinusitis in patients without allergic rhinitis, as they show no significant benefit for overall symptom improvement and may potentially worsen congestion by drying nasal mucosa. 1

Evidence on Antihistamine Use in Rhinosinusitis

Limited Efficacy in Non-Allergic Patients

• Antihistamines have no established role in the symptomatic relief of viral rhinosinusitis in non-atopic patients 1
• The European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS 2020) states that both studies evaluating antihistamines in rhinosinusitis showed no additive effect over standard treatment 1
• Based on very low quality evidence, the EPOS 2020 steering group cannot advise on the use of antihistamines in post-viral acute rhinosinusitis (ARS) and acute bacterial rhinosinusitis (ABRS) 1

Potential Risks in Non-Allergic Patients

• Antihistamines may worsen congestion by drying the nasal mucosa in patients without allergic components 1
• First-generation antihistamines can cause sedation, performance impairment, and worsen sleep architecture 2
• The risk-benefit ratio does not favor antihistamine use in non-allergic rhinosinusitis 1, 3

Limited Evidence in Allergic Patients with Rhinosinusitis

• One randomized controlled trial in adults with both allergic rhinitis and acute bacterial rhinosinusitis found that loratadine (10mg) significantly decreased nasal obstruction (MD=−0.58; 95% CI =−0.85-−0.31, p<0.01) but did not reduce total symptom scores or rhinorrhea symptoms 1, 3
• Similar results were noted at day 14 with significantly decreased nasal obstruction (MD=−0.34; 95% CI=−0.64-−0.04, p=0.02) but no improvement in total symptom scores or rhinorrhea symptoms 1
• A study in children found that adding a decongestant-antihistamine combination to amoxicillin showed no benefit, concluding that "decongestant antihistamine need not be given to the child with acute maxillary sinusitis" 1

Appropriate Use of Antihistamines in Rhinitis

When Antihistamines May Be Considered

• Antihistamines may be considered in patients with viral rhinosinusitis who have a significant allergic component to their symptoms 1, 4
• Second-generation antihistamines are preferred over first-generation options due to their improved safety profile and reduced sedative effects 4
• In allergic patients, second-generation H1-antagonists cause less sedation and anticholinergic side effects than older first-generation H1-antagonists 1

Choice of Antihistamine When Indicated

• If an antihistamine is needed for a patient with allergic components, second-generation options (loratadine, desloratadine, cetirizine, fexofenadine) should be selected 4, 2
• Intranasal antihistamines may be more effective than oral antihistamines for nasal congestion when allergic rhinitis is present 4
• Fexofenadine, loratadine, and desloratadine do not cause sedation at recommended doses 4

Clinical Approach to Viral Rhinosinusitis

First-Line Management

• Viral rhinosinusitis is a self-limiting disease that typically resolves without specific treatment 1
• Nasal saline irrigation may improve quality of life, decrease symptoms, and decrease medication use 1
• Topical decongestants may be used for short periods (no more than 3-5 consecutive days) to reduce congestion 1

When to Consider Antihistamines

• Only consider antihistamines when there is clear evidence of allergic components to the patient's rhinosinusitis 1, 3
• In patients with known allergic rhinitis who develop viral rhinosinusitis, continuing their antihistamine therapy may help manage the allergic component 4
• Avoid antihistamines in elderly patients and children under 6 years due to increased risk of adverse effects 4

Common Pitfalls to Avoid

• Prescribing antihistamines for viral rhinosinusitis without allergic components 1
• Using first-generation antihistamines which can cause significant sedation and cognitive impairment 2
• Assuming all second-generation antihistamines have identical sedation profiles 4
• Overlooking that intranasal corticosteroids are more effective than antihistamines for controlling the full spectrum of nasal symptoms 4