Acupuncture at the Sphenopalatine Ganglion in the Treatment of Moderate-to-severe Seasonal Allergic Rhinitis

Allergic rhinitis (AR) is an immunoglobulin E-mediated inflammatory disease1 caused by hypersensitivity of the immune system to an allergen, affecting 100 million people in Europe 2and 400 million of the global population.The etiology of AR is multifactorial, resulting primarily from genetic predisposition, immunological response, and environmental pollutants.AR traditionally has been classified as seasonal (SAR) or perennial (PAR) depending on the causes and duration of symptoms. Some patients with AR prefer complementary and alternative medicine for their symptoms, with nearly 20% receiving acupuncture. According to the updated practice parameter of rhinitis in 2020, the use of acupuncture for the treatment of AR was not recommended due to a lack of well-controlled studies. The sphenopalatine ganglion (SPG), located under a thin (1-2 mm) layer of mucosa in the pterygopalatine fossa, consists of sensory fibers that innervate the nasopharynx, nasal cavity, and palate.Several studies have reported the benefit of SPG stimulation in chronic cluster headache and acute ischaemic stroke. Compared with traditional acupoints selected on basis of traditional meridian theory, acupuncture at SPG(inserting a needle through SPG acupoint (near ST7, Xiaguan) to reach and directly stimulate the SPG) may help patients ameliorate nasal symptoms immediately and improve quality of life by increasing sympathetic nerve excitability, but the evidence is inconclusive. We have designed this three-armed, randomized trial to investigate the efficacy and safety of acupuncture at SPG for the treatment of SAR. We hypothesize that acupuncture at SPG plus rescue medication is superior to sham acupuncture plus RM and RM alone in the treatment of SAR.