If you have a stubborn leg ulcer, you may be tempted to seed your wound with maggots, a treatment reportedly used on and off between the 14th and 20th centuries. But you may want to reconsider: maggots don’t help the wounds heal any faster than soothing gels, and the insects cause more pain.

Research in today's British Medical Journal shows that while maggots "clean," or remove a wound's dead tissue, a lot faster than a salve called hydrogel (which keeps a wound moist and helps clean it), they don’t actually heal it any quicker. What's more, patients who had loose or bagged larvae placed on their wounds reported experiencing more pain than those who used the gel. The findings are based on a group of 267 British patients; wounds treated with the gel healed in 245 days; those treated with maggots healed in 236 days, a difference that wasn’t statistically significant. The larvae, however, ate up the dead tissue in 14 to 28 days, versus 72 days by the gel.

"In terms of leg ulcers, maggots do not help them to heal — that’s the take-home message to me," Nicky Cullum, the study's chief investigator and a professor of health sciences at York University in England, tells ScientificAmerican.com. "They don’t offer an advantage and they are associated with pain."

Britain's National Health Service (NHS) funded the research, and maggot suppliers provided the larvae.

Cullum, who expressed skepticism about maggots as a first-line treatment for leg ulcers in a 2006 letter to the BMJ, undertook the study after the therapy was promoted in the U.K. in the late 1990s. "We may have overestimated how important cleaning is to healing," Cullum says. "Maggots do clean the wound quite rapidly and everyone thought it would lead to quicker healing, but it didn’t. Cleaning may not be so important to healing and [possibly] what matters is good bandaging."
Between half a million and 600,000 people a year in the U.S. suffer from venous ulcers, according to the Cleveland Clinic, often late in life after suffering a clot or other vein disease. Circulation problems that prevent the heart from adequately re-supplying the extremities with oxygen cause blood to pool in the legs, depriving the skin of the nutrients it needs to stay healthy. Because of these circulation problems, the wounds can persist for years, which may explain why patients were willing to have their flesh eaten to try to get rid of them.

Some 50,000 maggot treatments were given last year, Bloomberg News notes. The treatment works because maggots secrete enzymes that break down dead tissue, but it's not clear what role that process has in healing.

"There was a lot of enthusiasm because they have these wounds for a long time and are desperate for an effective treatment," Cullum says.

Image © iStockphoto/Sergiy Goruppa