September 18, 2001 8:00 CDT
A new study on osteoarthritis of the knee shows that leeches could possibly return as a popular treatment to relieve pain and inflammation. The study is reported in the Annals of the Rheumatic Diseases.
The study focused on 16 patients whose average age was 68, all of whom had persistent knee pain for more than six months. None had sustained knee injuries and all had x-ray evidence of osteoarthritis. Exercises, physiotherapy, relaxation techniques, and dietary changes were already part of their treatment program.
Ten patients took part in leech therapy, eight of whom were women. Six others were given conventional treatment for pain. The leech group had four leeches applied to the painful knee and left in place for one hour and 20 minutes. Pain measures were recorded three days before the start of the treatment and 28 days afterwards. The leech treatment produced rapid pain relief after three days, with the greatest effects coming 24 hours after treatment. The effects were sustained four weeks later. No side effects or infections were reported, although patients described the initial leech bite as somewhat painful. Pain relief was not evident in those receiving conventional treatment.
The authors state that leech therapy was once used to relieve pain and inflammation, but fell out of favor last century. They added that there are plausible explanations for the effectiveness of leech therapy, since leech saliva contains various analgesic, anesthetic, and histamine-like compounds. The authors admit that the study is small, but the results warrant further research with a larger number of patients.