Efficacy of seawater for the treatment of allergic rhinitis: a randomized clinical trial

Abstract

Objective: To evaluate the efficacy of diluted seawater (SW) nasal lavage and ingestion in the treatment of symptoms of allergic rhinitis, including nasal discharge, in children (2-6 years) compared with physiological “normal” saline solution (NS) as a control. Methods: Controlled, triple-blind, randomized clinical trial of 164 children with allergic rhinitis, drawn from schools and health centers located in areas with low socioeconomic status. Children were divided into two treatment groups: SW and NS. Clinical variables were evaluated at the beginning of the trial and at weeks 2 and 12. At the beginning and the end of the study an anthropometric growth check was performed. Results: 16 of the 164 children left the study early. There were 83 subject in the SW arm and 81 in the NS arm. In weeks 2 and 12, both groups achieved significant reductions in rhinorrhea (p<0.001) compared to baseline values (NS: Δ 36.3% (95% CI: 33.0 to 39.7) in week 2 and Δ 55.7% (95% CI: 52.3 to 59.0) in week 12; SW: Δ 32.0% (95% CI: 25.0 to 39.1) in week 2 and Δ 55.3% (95% CI: 42.2 to 62.3) in week 12). In both groups, instances of sneezing, itching and discharge were reduced (p<0.001). The SW group achieved larger reductions than the physiological NS group in dry cough, loss of appetite, nasal breathing and sleep quality at week 12; these differences were not significant. 14 cases of adverse effects were recorded. Between weeks 0 and 12 there were significant increases in height, weight and sitting height in both groups (p<0.001), and a slight reduction in BMI that was significant only in the SW group (p<0.05). Conclusions: Nasal lavage using either SW or NS was associated with significant improvement in allergic symptoms that were still detectable at 3 months. Both treatments seemed well tolerated. Both treatments were associated with improvements in anthropometric measurements. These findings should be confirmed in studies that include more subjects, last longer, and employ laboratory confirmation.