Efficacy, patients' perception, and cost of medication in allergic rhinitis with subcutaneous immunotherapy.

Background: Allergic rhinitis (AR) is the allergic inflammation of nasal mucosa. Treatment of AR includes pharmacotherapy and allergen immunotherapy. Subcutaneous immunotherapy (SCIT) is indicated in inadequate disease control, patient's preference, or impossible allergen avoidance. SCIT is an effective treatment but its cost is comparatively high. Efficacy, patient perception, and cost of medication are rarely explored in Asia.

Objective: To study efficacy, patient perception, and cost-benefit of SCIT in AR.

Methods: We performed a descriptive cross-sectional study at Thammasat University Hospital, Thailand. AR patients who had been receiving SCIT were interview. Current and recall of AR total symptom score (TSS), quality of life, and perception were scored. Cost of medications before SCIT and current cost were reviewed from the medical records.

Results: A total of 142 patients were enrolled. Sixty-eight patients (47.9%) received single allergen; house dust mite was the most common allergen. The median of maintenance phase was 47 months, range 15-142 months. The mean of current TSS was significantly lower than mean TSS before SCIT. Forty-two patients (29.6%) had discontinued SCIT on the day of the interview. After discontinuation of SCIT, TSS was still lower than TSS before SCIT. The average cost of medications including SCIT was lower than that of before SCIT with an average difference of 254.2 USD/year. Sixteen patients (11.3%) experienced systemic reaction, 8 of which had reaction during rush immunotherapy.

Conclusions: SCIT is an effective, cost-saving and safe treatment option for AR. Rush immunotherapy can reduce duration of build-up phase but increase the risk of systemic reaction.