Allergic rhinitis(AR) is one of the most common allergic disorders throughout the world.The
conventional therapies are effective in alleviating symptoms but the efficacy are limited and
not persistent. Furthermonre, the cost and side-effect are known defects. A classical Chinese
herbal formula, has been used for AR for centries. Our study purpose is to evaluate the
clinical efficacy and safety of this formula verus placebo in perennial allergic rhinitis
(PAR).
Hypothesis: the classical herbal formula would improve the symptoms of PAR patients and
change some immunological parameters in the peripheral blood when comparing with the placebo.