Maggot Therapy: How Sterile Little Bugs Speed Cleaning of Wounds

There's still some debate on whether they hurt more than a traditional scalpel, but the little creepy-crawlies are quick to digest dead tissue


Maggots may trump scalpels when it comes to cleaning large wounds that won't heal easily, such as those seen in diabetics, according to French researchers.

To allow such wounds to heal, doctors usually remove infected or dead tissue with scalpels or enzymes, a process they call debridement. But that method is time-consuming and doesn't always work.

Studies have suggested maggots might be helpful, potentially offering antibacterial and healing benefits in addition to keeping the wound clean -- although not all researchers are convinced insects are the way to go.

The new study was carried out in patients with so-called venous ulcers on their legs. During a two-week hospital stay, they were randomly assigned to either maggot therapy or traditional wound cleaning with a scalpel, with just over 50 patients in each group. Both groups of patients were blindfolded so they wouldn't know which treatment they received.

The sterile creepy-crawlies, of the species Lucilia sericata, came in little bags that were placed over the wounds twice a week. Maggots secrete substances into the wounds that liquefy dead tissue and then they ingest the material to further degrade it in their guts.

There was no difference in pain or crawling sensations between the two groups, according to Dr. Anne Dompmartin of Centre Hospitalier Universitaire de Caen and colleagues. Their findings appear in the Archives of Dermatology.

After one week, on average two-thirds of the wound area in patients who got surgical cleaning was covered with dead tissue known as slough, which interferes with healing. In patients treated with maggots, however, only 55 percent of the wound area was covered in slough. But the benefit vanished after two weeks, and there was no difference in wound closure.

"If clinicians and patients are primarily aiming to get wounds healed, maggots seem to offer no benefit and therefore are not a good option," said Nicky Cullum, a professor of nursing at the University of Manchester in the U.K., who has studied the use of maggots in wound care.

"Exactly as our previous study (did), it shows that maggots clean wounds more quickly than conventional treatment but with no benefit on healing," she said in an email to Reuters Health about the new research.

While the French patients experienced only "mild pain," Cullum said patients in her study had often complained of "severe pain."

"In real clinical life patients know whether they are receiving maggot therapy or not, therefore the pain we measured is likely to be what is reported by patients in real practice after the application of maggots," she said.

Maggots have been approved for medical use in the U.S. since 2004, but their availability varies.

The French team and Cullum both said the insects may be useful in preparing wounds for skin grafting, although Cullum cautioned that this hasn't yet been proven.

"We are suggesting it may be effective but we have no idea," she said.

Image: dabjola/Shutterstock.