Background:Allergic rhinitis is a nasal mucosa inflammatory disorder that is induced by exposure to an allergen which results in four major symptoms,including anterior or posterior rhinorrhea,sneezing,nasal itching and nasal congestion.Allergic rhinitis may result in sleep disturbance,fatigue,depression of mood-cognitive function and quality of life impairment.Objective:This study examined the efficacy and safety of herbal steam bath used for the reduction of allergic rhinitis symptoms,and evaluated treatment satisfaction and improvements in quality of life among participating patients with allergic rhinitis.Design,setting,participants and intervention:A single-blind randomized controlled trial was conducted at Thai Traditional and Altative Medicine Hospital between June and December 2016,using 64 subjects,equally divided into two groups.The treatment group received herbal steam bath and the control group received steam bath without herbs for 30 min 3 times a week for 4 consecutive weeks.Main outcome measures:Allergic rhinitis symptoms,such as itchy nose,runny nose,sneezing,nasal congestion and watery eyes,were measured using the visual analog scale at weeks 0,1,2,3 and 4.Quality of life was assessed at week 0 and week 4.Results:The characteristics (sex,age,marital status,education,allergic rhinitis symptoms and frequency of symptoms) at the baseline were not statistically different (P ＞ 0.05) between the two test groups.Anterior or posterior rhinorrhea symptoms,including sneezing,nasal itching and nasal congestion,were statistically reduced over the course of the treatment,but reductions were not significantly different between the control and treatment groups.The treatment group,however,was shown to be significantly more satisfied with the treatment than the control group (P ＜ 0.05).Conclusion:Both treatments appear to be able to significantly reduce the symptoms of allergic rhinitis.However,there was no difference in the effectiveness of steam bath with herbs and steam bath without herbs.