ESSEN, GERMANY. Leeches were used throughout antiquity and well into the 20th century for the treatment of pain and inflammatory diseases. The last few years have seen a rise in leech therapy with a reported 70,000 treatments now taking place in Germany every year. Researchers at the University of Essen have just completed a controlled pilot study to investigate the effect of leech therapy in relieving pain. The study involved 16 patients with painful osteoarthritis of the knee. Ten were treated once by the application of four leeches at the corners of the knee joint (front) for about 80 minutes. The six remaining patients were treated with conventional anti-inflammatory drugs. The patients undergoing leech therapy stopped their use of anti-inflammatories during the study period. All patients had their pain rated on a scale of 0 to 10 with 0 being no pain and 10 being extremely painful. The average pain score for the leech-treated patients was 7.4 at baseline, this decreased to 1.3 ten days after the treatment and remained at 1.0 28 days after treatment. In comparison the average pain score of the control patients was 4.8. It is known that the saliva of leeches contains a number of compounds with anaesthetic and analgesic properties. The researchers believe that these compounds, hyaluronidase in particular, are responsible for the pain-killing effects and urge further trials to confirm the benefits of leech therapy for osteoarthritis of the knee.
Michalsen, A., et al. Effect of leeches therapy (Hirudo medicinalis) in painful osteoarthritis of the knee: a pilot study. Annals of the Rheumatic Diseases, Vol. 60, October 2001, p. 986