A recent article in the Clinical Journal of Pain demonstrated that the use of leeches was more effective than topical diclofenac in controlling pain and disability in individuals with lateral epicondylitis pain.
The study was a randomized, controlled trial with 40 participants. The subjects were randomized into a group that recieved a single treatment of 2-4 leeches or a group that recieved a topic NSAID for 30 days.
The results showed a statistically significant decrease in pain ratings as compared to the control group after the first seven days. On day 45, both treatments had about equal effects on pain but the leech group experienced a higher decrease in functional disability as measured on the DASH. Surprisingly, no major adverse side effects were noted.
How does this work: The authors are relatively unsure. They suspect that the saliva in leeches helps to augment local blood flow while also releasing analgesic properties. They also suspect that a placebo response is elicited through the use of leeches. They state this may be due to the concept “the more impressive a treatment is, the bigger the unspecific effects are” or the use of leeches is more impressive/intriguing as compared to just another topical agent. This may have an effect of functional brain mapping.
Weaknesses: The study included a small sample size to determine mid- to long-term outcomes. There also should be a more comparable sham vs. a topical NSAID that has been shown to be effective in decreasing musculoskeletal pain.
Bäcker Marcus, Lüdtke Rainer, Afra Dani, et al.Effectiveness of Leech Therapy in Chronic Lateral Epicondylitis: A Randomized Controlled Trial. Clinical Journal of Pain 2011; 27: 442-447.