Risk-Oriented Clinical Management and Observed Safety Outcomes of Acupuncture in Patients at Risk of Metal Allergy: A Single-Center Retrospective Case Series

BACKGROUND: Acupuncture is widely used in complementary and integrative medicine. Because acupuncture needles are primarily made of stainless steel, patients at risk of metal allergy require careful management. However, evidence regarding risk-oriented clinical management and observed safety outcomes remains limited. This study aimed to describe risk-oriented clinical management and observed safety outcomes in routine acupuncture practice, including those at risk of metal allergy. METHODS: This single-center retrospective case series included consecutive new patients receiving acupuncture over 1 year. Electronic medical records were reviewed for metal allergy risk, clinical management, and adverse events. Patients were classified as at risk of metal allergy based on documented history, self-reported symptoms, or clinical findings. Clinical management was individualized based on risk assessment, clinical judgment, and patient preferences. Safety outcomes included metal contact allergic reactions, systemic metal allergy reactions, and other serious adverse events. RESULTS: Among 230 patients, 23 (10.0%) were classified as at risk of metal allergy. Clinical management included risk assessment, stepwise and minimally invasive approaches, consideration of alternative materials, and post-treatment monitoring. Among 22 patients, 220 treatment sessions were performed. No cases of metal contact allergic reactions, systemic metal allergy reactions, or other serious adverse events were observed. Likewise, no such adverse events were observed in the overall study population. CONCLUSION: This study provides a practice-based description of risk-oriented clinical management and observed safety outcomes in patients receiving acupuncture, including those at risk of metal allergy. The findings illustrate how patients at risk of metal allergy were assessed and managed in routine acupuncture practice, while the absence of observed adverse events should be interpreted cautiously given the limited sample size and observational study design.