Intranasal corticosteroids for non-allergic rhinitis.

backgroundNon-allergic rhinitis is defined as dysfunction and non-infectious inflammation of the nasal mucosa that is caused by provoking agents other than allergens or microbes. It is common, with an estimated prevalence of around 10% to 20%. Patients experience symptoms of nasal obstruction, anterior rhinorrhoea/post-nasal drip and sneezing. Several subgroups of non-allergic rhinitis can be distinguished, depending on the trigger responsible for symptoms; these include occupation, cigarette smoke, hormones, medication, food and age. On a cellular molecular level different disease mechanisms can also be identified. People with non-allergic rhinitis often lack an effective treatment as a result of poor understanding and lack of recognition of the underlying disease mechanism. Intranasal corticosteroids are one of the most common types of medication prescribed in patients with rhinitis or rhinosinusitis symptoms, including those with non-allergic rhinitis. However, it is unclear whether intranasal corticosteroids are truly effective in these patients.

objectivesTo assess the effects of intranasal corticosteroids in the management of non-allergic rhinitis. SEARCH

methodsThe Cochrane ENT Information Specialist searched the Cochrane ENT Register; Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 7); PubMed; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 1 July 2019. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing intranasal corticosteroids, delivered by any means and in any volume, with (a) placebo/no intervention or (b) other active treatments in adults and children (aged ≥ 12 years). DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. The primary outcomes were patient-reported disease severity and a significant adverse effect - epistaxis. Secondary outcomes were (disease-specific) health-related quality of life, objective measurements of airflow and other adverse events. We used GRADE to assess the certainty of the evidence for each outcome. MAIN

resultsWe included 34 studies (4452 participants); however, only 13 studies provided data for our main comparison, intranasal corticosteroids versus placebo. The participants were mainly defined as patients with perennial rhinitis symptoms and negative allergy tests. No distinction between different pheno- and endotypes could be made, although a few studies only included a specific phenotype such as pregnancy rhinitis, vasomotor rhinitis, rhinitis medicamentosa or senile rhinitis. Most studies were conducted in a secondary or tertiary healthcare setting. No studies reported outcomes beyond three months follow-up. Intranasal corticosteroid dosage in the review ranged from 50 µg to 2000 µg daily. Intranasal corticosteroids versus placebo Thirteen studies (2045 participants) provided data for this comparison. These studies used different scoring systems for patient-reported disease severity, so we pooled the data in each analysis using the standardised mean difference (SMD). Intranasal corticosteroid treatment may improve patient-reported disease severity as measured by total nasal symptom score compared with placebo at up to four weeks (SMD -0.74, 95% confidence interval (CI) -1.15 to -0.33; 4 studies; 131 participants; I AUTHORS'

conclusionsOverall, the certainty of the evidence for most outcomes in this review was low or very low. It is unclear whether intranasal corticosteroids reduce patient-reported disease severity in non-allergic rhinitis patients compared with placebo when measured at up to three months. However, intranasal corticosteroids probably have a higher risk of the adverse effect epistaxis. There are very few studies comparing intranasal corticosteroids to other treatment modalities making it difficult to draw conclusions.