Nine RCTs (n=648) were included in the review.
The quality scores assigned to the included studies ranged from 2 to 5.
Total nasal symptom score (6 RCTs, n=346).
Intranasal corticosteroids were associated with a significantly greater reduction in total nasal symptoms than topical antihistamines (SMD 0.36, 95% CI: -0.57, -0.14, P=0.0001). No evidence of statistical heterogeneity was found (P=0.26). A sensitivity analysis on study quality found that the difference was significant in higher quality studies (5 RCTs; SMD -0.42, 95% CI: -0.63, -0.2, P=0.002), but not in the lower quality studies (4 RCTs; SMD 0.55, 95% CI: -0.53, 1.62, P=0.3). An analysis according to rhinitis subtype found the difference was significant in patients with seasonal rhinitis (SMD -0.38, 95% CI: -0.64, -0.13, P=0.003), but not in patients with perennial rhinitis (SMD -0.33, 95% CI: -0.73, 0.07, P=0.1).
Nasal symptoms.
Intranasal corticosteroids were associated with significantly greater relief of sneezing in comparison with topical antihistamines (SMD -0.41, 95% CI: -0.57, -0.24, P=0.0001), based on 594 patients in 7 RCTs; there was evidence of statistical heterogeneity (P=0.002). They were also associated with a significant decrease in rhinorrhoea in comparison with topical antihistamines (SMD -0.47, 95% CI: -0.64, -0.29, P=0.0001), based on 523 patients in 6 RCTs; there was evidence of statistical heterogeneity (P=0.01).
Intranasal corticosteroids were associated with significantly greater relief of nasal itch in comparison with topical antihistamines (SMD -0.38, 95% CI: -0.56, -0.19), based on 460 patients in 5 RCTs; there was evidence of statistical heterogeneity (P=0.03). They were also associated with significantly greater relief of nasal blockage in comparison with topical antihistamines (SMD -0.86, 95% CI: -1.07, -0.64), based on 376 patients in 4 RCTs; there was no evidence of statistical heterogeneity (P=0.15).
Eye symptoms (4 RCTs, n=428).
No significant difference was found between intranasal corticosteroids and topical antihistamines for ocular symptoms (SMD -0.07, 95% CI: -0.27, 0.12, P=0.4); there was evidence of statistical heterogeneity (P=0.0001).
Nasal congestion (2 RCTs, n=52). No significant difference was found between intranasal corticosteroids and topical antihistamines for nasal congestion (SMD -0.01, 95% CI: -0.56, 0.53, P=0.9); there was no evidence of statistical heterogeneity (P=0.3).
Adverse effects (4 RCTs, n=526).
A low incidence of mild to moderate adverse events was reported. No difference between the treatment groups was observed.