Maggot Therapy Re-Emerging: Fly Larvae Doing “Grub” Work

To most people, maggots are not their idea of a medical treatment. However, to many doctors, fly larvae do have a place in modern medicine – that place being inside open wounds.

“It sounds horrible, but – by golly – it worked,” said Long Beach, Calif. resident Edmond Wicks, who underwent maggot therapy to treat face and leg wounds complicated by his diabetes.

“It actually works quite well,” confirmed 37-year-old Dr. Ron Sherman, who uses maggots to clean out, or debride, wounds.

It was late 1990 when Sherman began using maggot debridement therapy on a research basis. Since then, more than 1,000 patients – including a large number of people with diabetes – have been treated with maggots at the Long Beach Veterans Affairs Medical Center.

In these days of returning to natural medicine, when avoiding drugs and surgery is higher on people’s lists (leeching is making a comeback as well), maggots are being seen as small saviors.

Maggot debridement therapy is exactly what it sounds like: live fly larvae are mixed into a wound’s dressing and the area is covered with gauze. According to Sherman, maggots – which will only eat dead, also known as necrotic, tissue – feed on damaged flesh and leave the healthy tissue behind. In the process, the maggots – besides eating the dead tissue – excrete an ammonia-like anti-microbial chemical which helps cleanse the wound. When the dressing is cut away two or three days later, the gorged maggots – now up to 10 times their original 1 mm size – are easily removed.

Also according to Sherman, people with diabetes are among those with the most to gain from maggot debridement therapy.

Certain symptoms of diabetes, such as restricted circulation – which can lead to gangrene in extremities – as well as neuropathy (nerve damage) can result in the dead flesh that maggot therapy is used to remove, the California doctor said.

“Diabetics have several problems related to the deceased circulation and neuropathy,” Sherman said. “Probably the most common problem we see are foot and leg wounds due to the anesthesia and trauma. We use maggots there to help clean and heal some of these wounds. In several cases we’ve been able to avoid surgery.”

Foot wounds are especially common among people with diabetes. As Sherman said, neuropathy can cause anesthesia, allowing repeated small traumas – which people with neuropathy can’t feel – to the skin, causing it to break down (see Dr. Neil Scheffler’s story in the March 1995 issue of Diabetes Health).

Sherman said that in all cases, maggots have been able to clean the wound without damaging underlying tissue – the most positive aspect of maggot therapy.

“(Damaging healthy tissue) is certainly the greatest fear and anxiety when (doctors) see a wound on the foot of a diabetic and they want to remove the dead tissue,” he reported. “Doctors are afraid if they cut out the dead tissue, they will make the wound bigger and remove some healthy tissue in the process. (They fear that) because of the diabetic’s impaired healing, they may end up with an even greater wound.”

But that fear can be alleviated with maggot therapy.

“The wound looks like it’s getting bigger as it’s being cleaned out (by the maggots), but in fact only dead tissue is being removed and healthy tissue is not – that’s a great advantage,” said Sherman.

Impaired healing abilities in some people with diabetes is another concern.

“A second problem people with diabetes have is impaired wound healing – an open wound is going to be a site where infection can occur and recur,” Sherman said. “We’ve used maggot therapy to help clean these wounds as well.”

Wicks was plagued by slow-healing wounds when he was referred to Sherman.

“We had been doing everything without success,” he said. “(Sherman ) took one look at me and … proposed using maggots. I had to think it over for a couple of days.”

Both Sherman and Wicks said that the maggots helped Wicks’ wounds – which had been bothering him for about six months – to completely heal. Wicks had undergone 12 cycles of maggot therapy over two months.

The maggots on his face, and later his leg, were hardly noticeable, according to Wicks.

“(I felt them) a couple of times, but not too often,” he said. “Once one took a big bite out of me and I jumped – that guy must have been hungry.”

Maggot therapy is not new, having been used by such individuals as Napoleon’s battlefield doctors. According to Sherman, the therapy was really introduced to the United States in the 1920s when many cases of tuberculosis- and osteomyelitus-caused wounds were treated with maggots. However, the treatment was out of favor by the 1940s, he added.

According to Stedman’s Medical Dictionary, maggot therapy is “an obsolete therapy of wound debridement and removal of abscessed tissues by use of sterilized … maggots.” Sherman doesn’t think the word “obsolete” fits the method.

“We still have people saying it’s something from the dark ages,” he said. “(Doctors) who have used maggot therapy – there are a number of them – recognize the benefits.

“A lot of people have not seen the benefits, only know it as a piece of medical history and believe it is not useful anymore, especially those with their own modality to offer – such as surgery.”

Dr. Neil Scheffler, a Baltimore podiatrist who frequently treats diabetics with the sort of foot injuries Sherman thinks maggot therapy is optimized for, is one of the doubters.

“My first reaction is that there are other alternatives than using maggots to debride,” he said. But, he added, “There probably isn’t one ‘ideal’ method (to debride).”

Scheffler, who hadn’t previously heard of maggot therapy’s return to grace, said he hadn’t seen any recent information on the still somewhat obscure topic.

“My initial impression was ‘What?’ Then my question was, ‘Does it work better than some more conventional method?’ ” he said.

Several years after he worked with Dr. Edward Pechter – now a plastic surgeon in Valencia, Calif. – on a research paper, Sherman proposed using maggot therapy in Long Beach on a research basis. Pechter, who had previously seen cases of maggots naturally getting into wounds, approached Sherman with the idea of writing the paper after he saw the then medical student Sherman wearing a tie with butterflies on it.

Later, at Long Beach, Sherman had noticed a number of chronic wounds and had heard of cases where maggot therapy had cured wounds not being adequately treated by surgery or antibiotics. Now it is offered (almost) routinely – for those patients up to the idea.

“In general, patients do not react as reluctant as those of us who have no wounds think that they would,” said Sherman. “People who have had wounds for months, in my experience, find the thought of maggots no more repulsive than the fear of losing (a limb). It is not nearly so repulsive as what the alternatives are.”

Blowflies, rather than common houseflies, are the focus of Sherman’s work. The species he uses, Phanecia sericata, is one of three species that was regularly used in maggot therapy early in the century. Sherman raises maggots himself, in a special room at the hospital dubbed the “insectary” in which rotting pieces of meat are left out for flies to lay eggs on.

“We have several cages, each with a couple thousand flies. We regularly collect eggs, which are either sterilized and put in special bottles for (treatment) or are not sterilized so they live through their entire life cycle and are used to replace older flies,” Sherman said.

“We raise flies (at the hospital) so I have enough of a supply at all times and so I’m not dependent on anyone else.”

Some of Sherman’s patients have been referred to him by other doctors, and some – learning about Sherman from the great deal of publicity surrounding his treatment – have been self-referred. Sherman refuses to treat wounds that are life-threatening, will heal on their own, or involve large amounts of tissue destruction. Those patients are usually referred back to surgery. Still, maggot therapy has its advantages.

“The results are much more expedient than other non-surgical methods we have available,” Sherman said.

The doctor cautioned that maggot debridement therapy isn’t some mystical panacea when it comes to dealing with slow-healing wounds – especially for those with impaired circulation, such as many people with diabetes.

“Wound healing doesn’t occur readily … without a reasonable amount of blood circulation,” he said. “Maggots can debride, but (chances for) the wound to heal with no blood in the area are minimal at best.”

Otherwise, most doctors see no major problems with the therapy.

“It’s not the first thing I’d try,” Pechter said, “but it has its place in treating necrotic wounds.”

Also see our article “The World’s Tiniest Surgeons: Maggots Are All Over Foot Ulcers”, June 2007.

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