Maggots' Taste For Flesh May Cure Leg Ulcers

An ancient but uncommon therapy may help avoid amputation.

March 19, 2009, 3:37 PM

March 20, 2009&#151; -- With a worsening ulcer and the threat of losing a foot, Pam Mitchell was willing to try something drastic; she had live maggots put in her wound.

"I didn't have a choice, I didn't have any options, I had to have [it] amputated," she recalled.

But she heard about maggot therapy from a friend who had seen it on The Learning Channel. While it took some convincing of her doctors, Mitchell said they agreed to try it before amputation.

Her dermatologist, she recalled, said, "Why not, let's try it." The doctors sent off to a lab in California to have specially bred maggots shipped in, although Mitchell believes they probably did it to show her it wouldn't work.

But in Mitchell's case, it did.

Consuming the dead tissue, the maggots, it seems, were able to help the wound heal and prevent the foot from being amputated. In the course of 10 treatments with maggots, the ulcer in her foot, which had become a gaping hole before therapy, began to get better. Mitchell also took antibiotics to help avoid further infection.

"Every time we used them, my foot filled in a little bit more, each time," said Mitchell, 56, of Akron, Ohio, who now speaks about the therapy as a representative of the BioTherapeutics, Education & Research Foundation in Irvine, Calif.

The company is headed by Dr. Ronald Sherman, a now-retired professor at the University of California-Irvine who studied maggot therapy for more than 20 years in healing wounds that other therapies weren't repairing.

Now a new study in the British Medical Journal, headed by researchers at the University of York in England, reports that maggot therapy is about as effective as conventional therapies at healing leg ulcers. The fly maggots cleaned the wound slightly faster, but did not increase the overall rate of healing. Also, the maggot treatment was much more painful in the early stages.

"In people with leg ulcers, we didn't find that larval therapy increased healing rates," said Nicky Cullum, head of the Department of Health Sciences at the University of York. "It cleans it more quickly, but it didn't heal it more quickly."

Maggots Not a Turn-Off for Patients

But, like Mitchell, she found that patients were not averse to treatment with the maggots.

"One thing we did find is that patients were not put off. ...The patients were very enthusiastic," she said.

Cullum noted that the procedure, which had been used since ancient Rome, was likely without much hazard. It has been approved by both the United Kingdom's National Health Service and the U.S. Food and Drug Administration.

"There's no reason to suspect they're not safe," Cullum said.

Researchers used maggots from a species of fly known variably as the sheep blowfly or the green bottlefly, which is probably known to most people for its gathering around deceased humans and animals, although it can congregate around live ones as well.

But some questions remain.

While he declined to speak about the medical effectiveness of the therapy, Richard Wall, a zoologist at the University of Bristol, noted that there is no guarantee that the flies will not eat live flesh as well as the dead tissue.

"They will try to do so, if they are overcrowded," Wall said. "The key thing is that the number of maggots needs to be kept fairly low to prevent this; then they will feed happily on the [dead] tissue. So, working out the correct numbers is critical. When these maggots kill sheep, it's because you get very high numbers on a single animal."

Sherman, who has done a number of trials on maggot therapy during the years, said that he had not observed anything similar in humans. Although he noted that he tries to avoid having too many maggots on a wound, recommending five to eight maggots per square centimeter.

During her treatment, Mitchell said, there were too many maggots in her foot, which caused some pain when they swelled up after eating the dead tissue.

"When they come out, they're fat, like puffed rice," Mitchell said.

No Maggot Therapy in Medical School

"If it works, what's wrong with it?" said Dr. Eliot Ghatan, a dermatologist in Brooklyn, N.Y. "If you have a fancy medication here, it doesn't mean you can throw out effective therapeutic methods of the past."

He added, however, that, "It's not very well known. When you go to medical school, they don't teach you about maggot therapy."

Dr. Conway Huang, director of dermatologic surgery and cutaneous laser surgery at the University of Alabama, echoed those statements.

"It's not something that is taught to doctors in training. Residency programs ... we don't teach our residents this," he said. "Current methods of wound healing are probably more convenient and nearly as effective, if not as effective."

Despite their familiarity with the therapy, neither Ghatan nor Huang have performed it on a patient or had it requested by a patient.

For his part, Sherman said that while his own experience has been different, he was pleased that a maggot study was published.

"I think it's great news that they finally did a study of maggot therapy that follows patients all the way to wound closure," he said.

The therapy was researched heavily in the 1930s by Dr. William Baer at Johns Hopkins University in Baltimore, but was ultimately replaced by antibiotics, which remain the standard of care.

The British study, commissioned by the National Health Service, was done, in part, to determine the cost effectiveness of maggot therapy versus regular therapy. The researchers concluded that there was not a significant difference in cost effectiveness.

Sherman attributes that to the fact that the form of maggot therapy examined in the British study used more conventional drugs than his own version of the treatment.

While Sherman does not believe conventional treatments should be abandoned as the first line of treatment against skin ulcers, he hopes that maggot therapy will be recognized as an alternative when conventional therapies do not heal patients.

No One Product Works for Everybody

"Neither maggot therapy nor the standard of care is 100 percent effective, or else there wouldn't be 2,000 wound-care products on the market," he said. "The reason there are so many wound-care products is there isn't a single product that works for everybody, so what you want to do is pick something that has the best chance of efficacy.

"If that doesn't work, then you need an alternative, and you want that alternative to have the best chance."

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