As one of the most important concepts in traditional Chinese medicine, cutaneous regions have a close relationship with skin in modern medicine. According to the doctrine of traditional Chinese medicine, the cutaneous regions are the corresponding projections of twelve meridians in the superficial layer of the body and play an important role in body surface-viscera correlation. The symptoms of visceral disorders will reflect on cutaneous regions and one of the major patterns of manifestation is referred visceral pain accompanied by tenderness and hyperalgesia on the body surface. On the contrary, cutaneous regions participate in the treatment of visceral disorders. As major clinical applications of the cutaneous regions hypothesis, superficial acupuncture, subcutaneous needling, massage(tuina), moxibustion, and wrist-ankle acupuncture have achieved favorable therapeutic outcomes in clinical practice. Modern researches have gained insights into the biological background of cutaneous regions, however, further studies are needed to clarify the mechanisms.
Objective： Different kinds of sham acupuncture are widely applied in randomized controlled trials （RCTs） to explore whether acupuncture has intrinsic therapeutic effects beyond the placebo effects for certain indication. To make conclusions of trials more comparable and convincing, it is of great necessity to unify the sham acupuncture procedure. Methods： RCTs of acupuncture with high quality in the recent 14 years were reviewed, and the appropriateness of the sham acupuncture procedures was assessed. Results： The sham acupuncture procedures were mainly classified into five kinds according to their administered sites, penetrating, and intervention apparatus. Conclusion： Among the sham acupuncture procedures, needling near the selected acupoints, needling at a distant non-acupoints, and non-penetrating sham acupuncture are most commonly used. Sham acupuncture performed at distant site belongs to non-meridian and non-acupoint may be an ideal control for the study of the intrinsic therapeutic effects of acupuncture. Besides, the selection of controls must focus on the design and aim of RCTs, such as non-inferiority, equivalence and superiority trials.
