A Deeper Look at Maggot Therapy in Wound Care

When most people think about maggots, they may squirm with disgust. But believe it or not, the application of maggots by a trained medical professional is an effective treatment for hard-to-heal, chronic wounds.

The use of alternative methods, including leech therapy and maggot therapy, to treat wounds has been around for centuries.

“Having a discussion about maggots almost seems ridiculous juxtaposed to modern treatments,” said David G. Armstrong, DPM, MD, PhD, Professor of Surgery at the Keck School of Medicine, and Director of the Southwestern Academic Limb Salvage Alliance (SALSA) at the University of Southern California (USC) in Los Angeles.

In fact, Armstrong finds maggot therapy so effective he fondly calls maggots, nature’s microsurgeons. “In some cases, maggot debridement therapy (MDT) can eliminate the need for surgical debridement,” he said.

Types of maggots and how they’re used

Not all types of maggots are safe to use in wounds. MDT involves the use of a specific type of medicinal maggot, utilizing larvae from the blow fly. Armstrong said this maggot species is known by the scientific name of Phaenicia (Lucilla) sericata.

One reason these maggots work so well in treating hard-to-heal wounds is they digest necrotic tissue yet leave healthy tissue alone. The maggots accomplish this by releasing proteolytic enzymes that liquify the necrotic tissue, then they consume the liquid, said Armstrong.

MDT is a formally recognized treatment for wounds. In 2004, the FDA approved the use of medicinal grade maggots and categorized them as a medical device, he added.

Wounds that benefit from maggot therapy

The use of medical maggots for challenging wounds is not a first-line treatment. However, for slow-to-heal wounds in which other treatments have failed to produce an improvement, the use of maggots can be very effective.

“Most patients that come to see us at USC have typically already seen three or four other doctors for their wounds, and many other things have already been tried before in an attempt to heal their wound or wounds,” said Armstrong.

The types of wounds maggot therapy may be considered for are chronic, non-healing wounds such as:

• Diabetic foot ulcers (DFUs)
• Pressure injuries
• Post-surgical wounds
• Neuropathic foot ulcers
• Venous stasis ulcers

The advantages of maggots in wound care

Armstrong emphasized that while MDT does not compete against other treatments, it doesn’t provide a miraculous cure nor make a wound entirely disappear. However, “Maggot therapy can produce a synergistic effect in conjunction with other treatments to improve healing,” he added.

Armstrong described MDT as extremely helpful with:

• Extending the amount of time between surgical debridement
• Reducing the risk of infections
• Decreasing the amount of antibiotics needed
• Reducing the length of time antibiotics are used
• Lowering the number of clinical visits
• Increasing the length of time between clinical visits (especially helpful for patients with other complications and multiple providers)

According to Armstrong, extending the time between surgical debridement, specifically for high-risk patients with comorbidities, is advantageous for the following reasons:

• Allows time for patients to undergo other procedures as needed
• Reduces risk of exposure to communicable diseases such as COVID-19 by avoiding a hospitalization
• Delays a trip to the operating room for surgical debridement (helpful for patients who are not medically stable for surgery)

Challenges with medical maggots

One challenge with MDT is the “ick” factor. Armstrong pointed out some people feel squeamish when thinking about the use of maggots in wound care. But over the years, most of his patients agreed to the treatment and are not turned off by it.

“I’ve used MDT on numerous patients. And contrary to what one would think, most people agree to have it. Only a few have declined from this type of care,” he said.

With any medical procedure, there is always a chance patients can experience pain. According to Armstrong, while most patients do not feel pain with MDT, it is possible, but it isn’t common. Most contraindications for MDT are relative, he added. “There are no absolute contraindications other than, do not use MDT on someone with a raging infection. It won’t cure an infection, nor will it cure vascular disease.”

Where maggot therapy is performed

MDT is typically performed in outpatient clinics but can be administered in the hospital and even at home in some cases, said Armstrong. The first patient Armstrong is aware of to have MDT performed at home was early in 2020.

The COVID-19 pandemic created a new set of challenges for clinicians and patients receiving MDT. Armstrong recalled he had just treated a patient with a vascular intervention early in 2020. Soon after, the patient needed wound debridement. Next, the COVID-19 pandemic happened, and everything shut down.

“No one could get in the hospital. We couldn’t bring the patient in to perform surgical debridement,” he said. “And due to rules and regulations, we couldn’t surgically debride him at home. Larvae was the best option.”

Armstrong said the patient had a good support system at home with a caring family and great home health nurses. In fact, the nurses and family were willing to learn how to apply the maggots, he said.

The medicinal maggots were delivered to the patient’s house. Telehealth was utilized for teaching the nurses and family how to apply the maggots. A special app was used to digitally measure the patient’s wound progress. And a few months after this care, the patient was taken to the OR for a skin graft, he said.

Armstrong and some of his colleagues wrote an article on this first, at-home, telehealth maggot therapy case.

Administering MDT

Maggot therapy has become easier to perform as there are dressings now that come with the maggots attached, said Armstrong. Because maggot therapy is easier to use, he would like to see it utilized more for patients at home.

“It’s not laborious or complex to perform maggot therapy but some technique is involved,” he said. “You order the dressings and maggots, apply them, and change the maggot-infused dressings every three to four days.”

It’s important to follow the proper steps and use the right products, as you don’t want to suffocate the maggots, he said. If you are not using maggot-infused dressings, there are additional steps in the process, including coating the peri-wound skin with a protectant.

Armstrong said, these maggots are safe. They won’t crawl into other areas. They stay within the wound. “The paradox here is that it sounds revolting and gross, but it seems to draw people in.”