Maggot Therapy: Is It Viable In Wound Care?
Yes, maggots are inexpensive, practical and can facilitate the use of other modalities, says David G. Armstrong, DPM.
I remember bringing up the issue of using maggots to help debride a particularly intractable wound with one of my great mentors, Bill Todd, DPM, who is now with the Dr. William A. Scholl College of Podiatric Medicine at Finch University. What was his response? “Armstrong … Those damn critters have a hell of a lot less education than we’ve wasted on your sorry cranium. I should hope that you can at least learn to debride a wound as well as one of them.”
While I often think back on his diatribes—most of them with great pleasure—I think most about this one because of its novelty. It was the only time I could recall him being only half right. Without a doubt, most larvae did suffer from a lower quality of education than I did. However, I have never been able to equal them in terms of their zeal, their single-minded purpose, their individual ability to devour necrotic tissue and even their work ethic, although I must say I have tried.
Bill Todd also told us to try to work with folks who were better than we were—that way we might learn something. In my practice, I have endeavored to do this as well. In Tucson, Arizona, I learn from Brent Nixon, DPM, and I learn from Andrew Boulton, MD, in the United Kingdom. Along the way, I have befriended and worked with a lot of larvae. These partnerships have, for me, been very fruitful.
The use of medicinal larvae or maggot debridement therapy (MDT) has steadily increased in the past 10 years, particularly in many progressive, high-volume wound care centers and particularly in Europe and Asia. To date, the use of larvae to assist in treating wounds has been much less common in the United States.
However, the use of maggots has a very long history that may date back thousands of years. Ancient records suggest Mayans used dressings of beef blood set in the sun to heal wounds of the extremities. Australia also commonly used maggot therapy for gangrenous wounds.1 The use of MDT became more popular in the West in the latter part of the 19th century, as some empiricists began noting that wounds infested with maggots tended to heal more readily when the larvae were left in place, undisturbed.2-4
It was Baer in 1931 who perhaps first documented the intentional use of maggots for skin infections.5 MDT was then extensively utilized and researched until the early 1940s when the discovery, development and widespread dissemination of antibiotics caused this modality to fall out of favor. Yet, with the emergence of multidrug-resistant infections, an aging population and an exponentially increasing prevalence of chronic wounds in the West, this modality has seen a resurgence.
Understanding The Benefits Of Maggot Therapy
As most who have visited our center are well aware, we are very aggressive in our approach to diabetic foot wounds and espouse extensive surgical debridement as a cornerstone of care. We use MDT at our centers for chronic diabetic foot ulcerations that do not heal despite proactive local therapy in patients who are often not good candidates for wide area surgical debridement.
While this is our general principle of care, we will occasionly use MDT following intraoperative debridement. We have also used MDT extensively to prepare wound beds for use with numerous other modalities.
We have much to learn about the exact techniques employed by our non-human surgical colleagues. What we do know is very encouraging. They certainly work 24/7. They rarely complain and after 72 hours, you can kill them. These are, come to think of it, characteristics to which all of our podiatry residents should aspire.
We also know the larvae feed on the necrotic tissue and exudate of the chronic wound. You can see characteristic yellow-tinged exudate on inner and outer dressings following MDT, which generally corresponds to the degree of preexisting exudate in the wound and the vigor in which the larvae debride. This exudate may also assist in irrigating bacteria from the wound. Also be aware that maggot saliva and digestive secretions appear to have proteolytic and antibacterial properties.4, 6 Maggots may also help stimulate granulation tissue formation.2, 4
It is beyond the scope of this article to discuss our specific technique (see “Maggot Debridement Therapy: A Primer” in the July/August edition of the Journal of the American Podiatric Medical Association).7 There is certainly a small learning curve when using this type of therapy.
However, we can mention the practical aspects here. The University of California at Irvine is the only location in the U.S. where you can acquire the larvae (see contact info below). The current cost is approximately $70 for a jar of approximately 1,000 maggots, plus $19 for express shipping. While most literature suggests that the life span of the maggots in the jar before use is less than 48 hours, we have found that refrigeration has prolonged their pre-gustatory, pre-application life often to more than 96 hours.
In conclusion, there is an emerging body of knowledge that maggots are useful. In this era of high-tech gadgetry and space-age modalities, it is heartening and sometimes comical to see this very low-tech application juxtaposed next to, say, bioengineered skin. We must be aware however, that care of the diabetic foot in general and the wound specifically, is one of the last bastions of alchemy in medicine. Clinicians who can merge, mix and meld these seemingly disparate modalities will continue to be successful as we move into the next generation of care. I, for one, can’t wait. While I can’t speak for my larval colleagues, I’ll bet they feel the same way.
Dr. Armstrong is the Director of Research and Education within the Department of Surgery, Podiatry Section at the Southern Arizona Veterans Affairs Medical Center in Tuscon, Ariz. Dr. Armstrong is also a member of the Board of Directors for the American Diabetes Association.
Editor’s Note: This article was adapted from a previously published article in the July/August issue of the Journal of the American Podiatric Medical Association.
To acquire larvae from the University of California at Irvine, e-mail Ronald Sherman, MD at rsherman@UCI.edu or send a fax to (949) 824-1098.
No, it’s time-consuming and lacks proven efficacy, says Gary M. Rothenberg, DPM, CDE.
The 21st century has seen an exponential explosion of options for wound care. Some are variations of tried and true technology while others are more innovative and promising for faster and more effective healing. All practitioners who treat patients with wounds would agree the ideal modality would be simple — preferably for patient application — effective and pain/sensitivity-free. Maggot therapy is not commonly used because it does not meet these criteria.
Wound care is a time-consuming process. The average patient with an open wound is probably in my treatment chair for a minimum of 30 minutes. By the time you do a quick review of the patient’s overall medical status since the last visit, debride the wound, obtain possible X-rays, reiterate instructions for daily care and apply a dressing, a significant amount of time has elapsed. While the literature claims that learning how to use maggots in clinical practice is simple, it still requires significant training to yield successful outcomes.
Additionally, you must use a unique type of dressing to prevent the maggots from escaping. It is a multi-layered, cage-like dressing that frequently consists of hydrocolloid base, chiffon or nylon netting and absorbent gauze. With experience, the dressing may take an additional 30 to 45 minutes to apply, depending on the shape and size of the wound. Most people in private practice do not have the space or financial ability to keep these additional supplies on hand, not to mention the additional time to apply such a bandage.
While larval therapy may ultimately be easier for patients from the standpoint that they do not change the inner dressings at home, it is not simpler for the practitioner in organization or application.
Sterile medicinal maggots are only available from a few sources. They must be ordered, shipped and used within 12 hours of receipt. Once again, the practitioner is not going to have the maggots on hand even if he or she sees a patient with a potential wound for larval debridement. This is certainly a more cumbersome process than writing a script for a tube of ointment.
It is interesting that the literature also notes that maggot therapy frequently receives more resistance from medical practitioners than from patients. It is often doctors and nurses who oppose the use of insects for medicinal purposes and give this therapy its negative social stigma. Maggots are associated with dirt, decay and death, and some people will have a phobia against them. Certainly, some patients may be fearful, anxious or disgusted by the thought of maggot use on their bodies. Indeed, the education process itself for practitioners and patients alike is not simple.
Is There Proven Effectiveness?
Much of the literature regarding maggot therapy is still anecdotal and there is a paucity of randomized clinical trials comparing rates of healing using maggots versus other agents such as enzymatic debriding gels. It seems as though maggot therapy is reserved to a few geographic areas where it has been better received and to teaching institutions and training facilities. Maggot therapy is more commonly used in the United Kingdom and much of the literature is case-type studies and clinical experiences. Few practitioners worldwide are using maggots as a first line therapy for wounds. It is unrealistic to think a single three-day application of maggots will cure a wound that has been stagnant for months.
While dressings are similar in the case reports reviewed, it seems as though those using maggot therapy are unsure as to which dressings are best and there is still an element of trial and error in their development. The question must be raised that if maggot therapy is of so much benefit, why is it not used more often? The answer is because it is not substantially more effective compared to other modalities and because of its complexity.
What About Possible Complications?
Maggot therapy is not without potential complications. The most common side effect to maggot therapy is pain at the application site. Patients may actually feel a “nipping” or “picking” sensation that can be painful. This discomfort may be severe enough to require oral analgesics or, in some cases, the patient may request early termination of the treatment.
Other potential side effects of maggot therapy include intense local itching, transient fever, foul odor from the exudate and excoriations along healthy skin if the larvae escape. The most concerning complication for patients will invariably be failure of the dressing and escape of the maggots into their homes or public places. This potential treatment should be discussed with family and friends as social issues may make a patient very uncomfortable. Maggot therapy is complicated, has not been proven superior in its efficacy and clearly has an associated “yuck” factor.
Maggot therapy violates the “keep it simple” principle embraced by many practitioners. Wound care patients are often the most challenging from a medical standpoint and often have significant associated comorbidities. They are often debilitated, may reside in long term facilities, routinely have a full schedule of weekly doctor visits and may be undergoing other complicated medical treatments such as hemodialysis. Others may be active members of working society struggling not to allow a wound to interfere with family and work commitments. These patients need simple wound care regimes, not complicated dressings with prolonged applications that require frequent and rapid return to the doctor’s office or wound care clinic.
As physicians, we are trained to place ourselves in the place of our patients constantly. A doctor must constantly ask him or herself, “If I had this condition or problem, would I want that treatment done to me?”
It’s important to keep in mind that our current options for wound care modalities are phenomenal. Advances in technology have yielded growth factors, synthetic products for wound coverage and advanced antibiotics. Many of the current products or treatments are simple to use, promote rapid, safe healing and have few side effects. We have also been trained that all wounds are in evolution so you must change products and modalities frequently. In other words, you must evolve your care with the wound.
Maggot therapy may be limited to teaching institutions and few clinical practices because many people still consider it unconventional treatment. There are other simpler options for wound care that have scientifically proven efficacy and safety profiles. Maggot therapy is not part of my wound care armamentarium because I simply would not want to experience the nipping and picking sensation of maggots on me.
Dr. Rothenberg is a Certified Diabetes Educator who practices in Atlanta.
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2. Mumcuoglu KY, Ingber A, Gilead L, et al. Maggot therapy for the treatment of diabetic foot ulcers. Diabetes Care. Nov 1998;21(11):2030-2031.
3. Sherman RA, Sherman J, Gilead L, Lipo M, Mumcuoglu KY. Maggot debridement therapy in outpatients. Arch Phys Med Rehabil. Sep 2001;82(9):1226-1229.
4. Vistnes LM, Lee R, Ksander GA. Proteolytic activity of blowfly larvae secretions in experimental burns. Surgery. Nov 1981;90(5):835-841.
5. Baer WS. The treatment of chronic osteomyelitis with the maggot. J Bone Joint Surg. 1931;13:438-475.
6. Mumcuoglu KY, Miller J, Mumcuoglu M, Friger M, Tarshis M. Destruction of bacteria in the digestive tract of the maggot of Lucilia sericata (Diptera: Calliphoridae). J Med Entomol. Mar 2001;38(2):161-166.
7. Armstrong DG, et. al. Maggot Debridement Therapy: A Primer. J Am Podiatr Med Assoc 92(7):398-401, 2002.