Localized Acquired Hypertrichosis After Long-Term Repeated Cupping Therapy: A Case Report

Objectives: Cupping therapy applies negative pressure to the skin and is widely used for musculoskeletal disorders. Although generally considered safe, local cutaneous reactions may occur. Localized acquired hypertrichosis is characterized by excessive hair growth confined to a specific area and has been reported following repeated local stimulation such as trauma, inflammation, or mechanical stress. However, localized acquired hypertrichosis following repeated cupping therapy has not been reported.Methods: A 51-year-old male with a history of tonsillar squamous cell carcinoma treated with neck dissection and radiotherapy had persistent soft tissue stiffness in the posterior neck and shoulder region. Although cupping therapy had been performed intermittently on other body regions since 2021, repeated cupping therapy was specifically applied to fixed sites in the left posterior neck and upper trapezius region once or twice weekly beginning in September 2023. No medications or conditions associated with hypertrichosis were present during the observation period.Results: After approximately two years of repeated cupping therapy, localized hair growth developed exclusively within the cupping-treated areas, with sharply demarcated margins corresponding to the application sites and no similar findings in surrounding or contralateral areas.Conclusions: This case suggests a possible association between long-term repeated negative pressure stimulation and localized hair growth. Clinicians should be aware that prolonged repeated cupping therapy may induce unexpected localized cutaneous responses.