Saliva secretion in patients with allergic rhinitis

Area of Science:

• Otolaryngology
• Pharmacology
• Immunology

Background:

• Allergic rhinitis commonly causes watery nasal discharge, but its oral cavity fluid volume effects are unclear.
• Newer antihistamines are reported to have low dry mouth incidence, based solely on subjective patient accounts.
• Salivary gland function in allergic rhinitis patients treated with loratadine or fexofenadine remains under-investigated.

Purpose of the Study:

• To investigate the impact of loratadine and fexofenadine on salivary gland function in allergic rhinitis patients.
• To compare salivary gland function between treated allergic rhinitis patients, untreated allergic rhinitis patients, and healthy controls.
• To objectively assess dry mouth parameters beyond subjective patient reports.

Main Methods:

• A comparative observational study design was employed.
• Patients were categorized into four groups: fexofenadine-treated, loratadine-treated, untreated allergic rhinitis, and healthy controls.
• Salivary gland function was assessed using sialometry, alongside patient-reported xerostomia intensity.

Main Results:

• Patients treated with fexofenadine and untreated allergic patients reported the highest xerostomia intensity.
• Sialometry values were significantly lower in fexofenadine-treated and untreated allergic groups compared to healthy controls (p=0.02, p=0.03).
• Despite statistical differences, average sialometry exceeded 0.2 ml/min, and subjective dry mouth sensation was generally mild.

Conclusions:

• Allergic rhinitis patients exhibit altered salivary flow rates compared to healthy individuals.
• Fexofenadine treatment was associated with significantly lower salivary flow rates than observed in healthy individuals.
• While differences exist, the clinical intensity of dry mouth was low across all study groups.