Maggots: Much-maligned, but medically helpful

Maggots.

When you read this word, what comes to mind? Rotting meat? A grisly (and gristly) scene from a zombie flick?

Well, how about a doctor's office? No? Then you might be surprised to learn that the much-maligned maggot has found a niche in the medical world: clearing dead tissue from skin ulcers and other chronic wounds to promote healing. In fact, specially grown maggots are FDA-approved for this purpose, as they can safely clear (i.e., consume) dead tissue without harming the healthy tissue nearby.

One particular area where maggots have found wriggle room is in the cleaning of leg ulcers. These are sores on the lower leg that can take a long time to heal—up to a year for many people. There have been reports that maggots, which are the wormlike larvae of flies, work quickly to remove dead tissue from these ulcers, reduce the risk of infection and encourage faster healing. Now, the first large, good-quality study has put these claims to the test.

The study included 267 people with leg ulcers who received one of three treatments: maggots bagged in a sterile pack; maggots loose from a sterile container; or a hydrogel dressing, which is often used to keep ulcers moist and get rid of dead tissue. Whether in packs or free-roaming, the maggots were kept in place with a light covering. The hydrogel or maggots were replaced as needed until the dead tissue was gone.

The study found that maggots cleared the tissue much faster than the hydrogel dressing. Once researchers took into account other factors that might have affected these results, they concluded that both types of maggots worked around twice as fast as the hydrogel dressing.

However, contrary to expectations, clearing the dead tissue faster didn't mean that the ulcers healed more rapidly, as the rate of recovery was similar whether maggots or the dressing had been used. (Incidentally, this finding made researchers question whether removing dead tissue is as important to ulcer healing as is widely thought. But this is a matter for a future study.)

Researchers also found no difference between the treatments in how much bacteria was in the ulcers, including a particularly dangerous one called MRSA (short for methicillin-resistant Staphylococcus aureus). However, they didn't look for other specific types of bacteria, so they can't say whether other varieties might be more or less common with these treatments.

Adverse effects weren't any more likely with maggots than with the dressing. But researchers did find that people being treated with maggots reported more ulcer pain in the 24 hours before their first application was removed.

These findings might not be as glowing as some maggot enthusiasts would hope, but they do confirm that these wriggly critters are speed cleaners when it comes to removing dead tissue. This, say the researchers, could make them especially useful for rapidly preparing a wound before a skin graft or another type of surgery.

What you need to know. The researchers don't recommend using maggots rather than a hydrogel dressing for leg ulcers, as ulcers cleaned with either treatment healed at about the same rate. But maggots do appear to be a worthy alternative. More studies will need to explore how well they work for other types of wounds, including diabetic foot ulcers, bed sores, and wounds from surgery and trauma that aren't healing through regular means.

In the meantime, if your doctor suggests using medical maggots, don't just dismiss them out of hand. These critters may make your skin crawl but they might also help it to heal.

—Sophie Ramsey, patient editor, BMJ Group

ConsumerReportsHealth.org has partnered with The BMJ Group to monitor the latest medical research and assess the evidence to help you decide which news you should use.

Read more on "creature cures," and take a look at our Treatment Ratings (subscribers only) for leg ulcers.

Comments

[Dr M Sullivan]

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