An Updated Review of the Efficacy of Cupping Therapy

This systematic review represents an important milestone in cupping therapy research, analyzing 135 randomized clinical trials published between 1992 and 2010. Cupping therapy, an ancient practice of traditional Chinese medicine that uses suction cups to create skin suction, has been increasingly studied scientifically because of its growing use in Chinese hospitals and worldwide. The investigators conducted a comprehensive search across six databases, including both Chinese and international sources, to assess the efficacy of this therapy for various clinical conditions. The most studied types of cupping therapy were wet cupping (57.78% of studies), in which small incisions are made in the skin before cup application, followed by retained dry cupping (17.04%), moving cupping (8.89%), and flash cupping (7.40%).

The most commonly treated conditions included herpes zoster, facial palsy (Bell palsy), cough and dyspnea, acne, lumbar disc herniation, and cervical spondylosis. The meta-analyses performed demonstrated promising results, especially when cupping therapy was combined with other therapies. For herpes zoster, wet cupping proved significantly superior to conventional antiviral medications, with a relative risk of cure of 2.07. In addition, it significantly reduced the incidence of postherpetic neuralgia, a common painful complication of this condition.

In facial palsy, both flash and wet cupping, when combined with acupuncture, demonstrated efficacy superior to acupuncture alone, with relative risks of cure of 1.51 and 1.60, respectively. For acne treatment, cupping therapy proved twice as effective as medications such as tetracycline and ketoconazole. In cervical spondylosis, the combined therapy showed a cure rate 52% higher than the isolated treatments. An important aspect highlighted by the authors was the safety of cupping therapy, with none of the 135 studies reporting serious adverse effects.

However, the review also revealed significant methodological limitations in the quality of the analyzed studies. According to the Cochrane risk-of-bias assessment criteria, 84.44% of the studies were classified as high risk of bias. Common problems included inadequate description of randomization methods, lack of adequate blinding, and use of non-standardized efficacy criteria. Many studies used composite measures of efficacy categorizing outcomes into four grades ('cured', 'markedly effective', 'effective', and 'ineffective'), classifications that are not internationally recognized.

The authors emphasize that, although the results are encouraging, clinical trials of higher methodological quality and with larger samples are needed to definitively confirm the efficacy of cupping therapy. They also recommend that future research follow international standards such as CONSORT and adapt the STRICTA guidelines for acupuncture therapies, including details about types of cups, application points, theoretical basis from traditional Chinese medicine, practitioner experience, and number and frequency of treatment sessions.