Urticaria is a common skin disorder and 15-25% of people experience at least one attack of urticaria during their lifetime. Urticaria can be divided into acute urticaria (AU) and chronic urticaria (CU) according to the disease duration. CU is classified as either chronic autoimmune urticaria or chronic idiopathic urticaria.~In Chinese medicine theory, Urticaria is usually associated with either internal or external wind pathogen. Wind as a pathogenic factor is characterized by sudden onset and rapid changes in symptoms, and when resulting from an internal deficiency, it often leads to dryness.~Several research groups have conducted clinical studies to evaluate the efficacy of Chinese herbal medicine for the treatment of CU in recent decades. Among different Chinese herbal formulae for urticaria, Xiao-Feng Powder (XFP), also known as Wind-Dispersing Powder, is one of the most frequently used Chinese herbal formulae for CU, also has been widely used in Chinese medicine dermatology to expel wind and eliminate dampness, clear heat, nourish the blood and stop itchiness. Moreover, other researchers have found that XFP is effective in inhibiting inflammation, allergy, and oxidative stress in allergic skin diseases.~Investigators hypothesize that mXFP is effective and safe for the treatment of CU. In this study, eligible subjects will be randomized to receive either mXFP or placebo twice daily for 12 weeks followed by post-treatment visits at week 16. Subjects will take the standard therapy of antihistamines regularly for the first 6 weeks and then on on-demand basis for the next 6 weeks during the treatment period.
Urticaria is a common skin disorder and 15-25% of people experience at least one attack of urticaria during their lifetime. Urticaria can be divided into acute urticaria (AU) and chronic urticaria (CU). CU is more common in adults, and affects women more frequently than men. According to Chinese medicine (CM) theory, CU is known as Yin Zhen. Nowadays, CM is widely used for managing CU in Hong Kong and mainland. Among different Chinese herbal formulae for urticaria, Xiao-Feng Powder (XFP), also known as Wind-Dispersing Powder, is one of the most frequently used Chinese herbal formulae for CU.~This study used modified Xiao-Feng Powder (mXFP) to evaluate the effectiveness and safety of mXFP in treating CU. Hence, a double-blind, randomised, placebo-controlled clinical trial design with strong scientific rigor will be employed in this study, and it would be able to provide robust clinical evidence on the efficacy and safety of mXFP for CU.