Adverse events of auricular therapy: a systematic review

The aim of this study was to systematically evaluate the literature on adverse events associated with auricular therapy (AT). Case reports, case series, surveys, and all types of clinical trials reporting adverse events of AT were included. Relevant articles were mainly retrieved from 13 electronic databases and seven Chinese journals on complementary medicine. AT-related adverse events were reported in 32 randomized controlled trials, five uncontrolled clinical trials, four case reports, and two controlled clinical trials. For auricular acupuncture, the most frequently reported adverse events were tenderness or pain at insertion, dizziness, local discomfort, minor bleeding and nausea, and so forth. For auricular acupressure, local skin irritation and discomfort, mild tenderness or pain, and dizziness were commonly reported. Skin irritation, local discomfort, and pain were detected in auricular electroacupuncture, and minor infection was identified in auricular bloodletting therapy. Most of these events were transient, mild, and tolerable, and no serious adverse events were identified. Our findings provide preliminary evidence that AT is a relatively safe approach. Considering the patient's safety, prospective or retrospective surveys are needed in future research to gather practitioner-reported and patient-reported adverse events on AT, and the quality of adverse events reporting in future AT trials should be improved.