The Effects of Using Yupingfeng Powder With Variation for the Treatment of Allergic Rhinitis (AR): a Randomized Controlled Trial

Rhinitis is broadly defined as inflammation of the nasal mucosa. It is a common disorder that affects up to 40% of the population. Allergic rhinitis (AR) is the most common type of chronic rhinitis, affecting 10-20% of the population, and evidence suggests that the prevalence of the disorder is increasing. Severe AR has been associated with significant impairments in quality of life, sleep and work performance. AR is a prevalent clinical disease that can occur at any age. The pathogenesis of this disease is mainly due to that patient has an allergic physique. Still, it is also related to patients' living habits and affected by the patients' living environment.

AR is an IgE-mediated chronic inflammatory disease of the upper airways characterized by symptoms of sneezing, rhinorrhea, nasal itching, and nasal obstruction. However, not only this disease is difficult to cure, but also its relapse rate is high, therefore exerting a certain impact on their daily life, work and study. If the condition is not handled properly, it can cause various complications such as sleep disturbance, general fatigue, loss of appetite, loss of attention and disturbance to learning.

The development of AR requires an interaction between the environment, immune system, and genetic susceptibility. Several cells, cytokines, and chemokines orchestrate and maintain allergic inflammation. Cytokines play an essential role in mediating allergic inflammation. The importance of the T helper cell (Th) 2 cytokines in both the development of allergic sensitization and pathology of allergic inflammation is well established. While healthy subjects are predominated by Th1-type cells, nasal mucosa and epithelial tissues of AR subjects are dominated by Th2-type lymphocytes. AR is determined by a disequilibrium of T helper cells with a predominance of Th2-type cytokines but normal levels of Th1-type cytokines. Another subtype of T-cell, regulatory T-cell (Tregs), suppresses both Th1 and Th2-type cytokine expression. Thus, it has been suggested that in AR, an imbalance between Th2 and Treg-cells exists as well.

Characteristic cytokine known for Th1 cell such as IFN-γ is a key cytokine in bridging the innate and the adaptive arms of the immune system. In addition to its role in the development of a Th1-type response, IFN-γ plays a role in the regulation of local leukocyte-endothelial interactions.

On the other hand, Tregs has restrictive influences on both Th1 and Th2 cell-mediated inflammation. The lack of Tregs causes the emergence of allergic inflammation along with the increase in Th2 cells. The Tregs bring the allergic inflammation under control by synthesizing IL-10 and the transforming growth factor-β (TGF-β). Allergic patients show an allergen-specific functional defect in Treg that promotes Th2 polarization and consequently IgE synthesis.