Background: Short message service (SMS) has been suggested as an effective method to improve adherence to medical therapy in some chronic diseases. However, data on the effects of SMS interventions to allergic rhinitis (AR) treatment is limited at present. We aimed to assess whether a daily SMS reminder could improve AR patients' adherence to medication and treatment outcomes. Methods: Fifty outpatients with AR were randomized to either receive (SMS group) or not (control group) a daily SMS reminder on their cell phone to take intranasal corticosteroid treatment for 30 days. The primary study outcomes were self-reported adherence to medication, clinic attendance rate, and severity of AR symptoms using a visual analogue scale (VAS). Secondary outcomes were changes in nasal patency (minimum cross-sectional area, nasal cavity volume, and nasal airway resistance) and exhaled nasal nitric oxide levels. Results: Self-reported adherence to medication in the SMS group (15/25, 60%), was significantly higher than in the control group (7/25, 28%, p = 0.02). Similarly, the clinic attendance rate in the SMS group (72%) was significantly higher than in the control group (40%, p = 0.02). Although the VAS score improved significantly from baseline in both study groups, the improvement in the SMS group was significantly greater than in the control group (4.38 +/- 4.38 vs. 8.74 +/- 6.54, p = 0.031). No significant differences were observed between the two groups for the secondary outcomes. Conclusions: A daily SMS reminder may be an effective intervention to improve adherence to medication and treatment outcomes in AR patients. (C) 2013 S. Karger AG, Basel