Maggot therapy

What is maggot therapy?

Maggot therapy involves the use of maggots of the green-bottle fly, which are introduced into a wound to remove necrotic, sloughy and/or infected tissue. Maggots can also be used to maintain a clean wound after debridement if a particular wound is considered prone to re-sloughing.

Doctors and tissue viability specialists who have found that maggots are able to cleanse wounds much more rapidly than conventional dressings have reintroduced the technique into modern medicine.

While maggots improve the condition of a wound and allow the process of healing to begin, they should not be regarded as a cure for all types of wounds, by removing dead tissue and any associated bacteria.

How does maggot therapy work?

They physically feed on dead tissue and release special chemicals into the wound that break down dead tissue into a liquid form that the maggot can easily remove and digest.  The feeding maggot also takes up bacteria, during this process, which are then destroyed within their gut. It is an effective process that the larvae can often clean a wound within a few days.

How big are the maggots?

The maggots that are applied to your wound are very small, only a few millimetres in length, smaller than a grain of rice. During the treatment time they will increase in size as they clean the wound, to a maximum of 12mm.

How are the maggots applied?

There are two methods of application:

• BioBag dressing: The maggots are sealed within a dressing which is a finely woven net pouch containing a small piece, or pieces of foam, which aid the growth of the maggot and manage exudate. The BioBag dressings come in different sizes and are applied according to the nature and size of the wound being treated. The maggots remain sealed within the dressing throughout the treatment.
• Free range maggots: The maggots are applied directly onto the wound and retained within a special dressing system. The exact nature of this is determined by the size and location of the area to be treated.

How long does the treatment last?

This can vary with each treatment of maggots and the method of application being used. BioBag dressings can be left in place for up to four days—it is possible for the dressing to be removed on a daily basis to allow inspection of the wound site.

‘Free range’ maggots are generally left in place for up to three days before being removed from the wound site. With both application methods, it is impossible to predict how long a course of treatment will take. Sometimes a wound is completely cleansed by a single application of maggots but other wounds may require two or more treatments to achieve the desired effect.

Will I notice anything different during maggot therapy?

During maggot therapy you may notice some changes in the wound:

• The wound may become a little wetter than usual or show the presence of a dark red or pink discharge. This is due to the action of the maggot breaking down the dead tissue.
• Sometimes a wound that contains a lot of dead tissue will develop a characteristic smell during treatment. This is nothing to worry about, it is just due to the activity of the maggots and should disappear when the dressing is changed.
• Most people are unaware of the maggots presence, although a small number of patients claim that they can feel the maggots moving but only describe this as a tickling sensation.
• Some patients, particularly those with poor circulation report that their wounds become more painful during maggot therapy but this can be controlled with medication.
• Some patients have found that the pain associated with infected wounds is reduced following maggot therapy.

Will Maggots bury into healthy tissue?

The maggots used in wound management will not attack or bury into healthy tissue, they only remove dead tissue.

Will the maggots multiply in my wound?

Only adult flies can lay eggs, so the maggots cannot reproduce or multiply within the wound. 

Where do the maggots come from?

Maggots are produced in a special unit by highly trained staff at Biomonde, a company with many years of experience in wound management.

Are there any activities that should be avoided during treatment?

Although it is possible for the patient to carry out most normal activities while undergoing maggot therapy, they should ideally not bathe or immerse the wound in water.

It is also not a good idea to sit with the wound too close to a source of heat eg fire or radiator as the maggots may dry out. Similarly, sitting or walking on a wound treated with maggots should also be avoided as much as possible.

Why use maggot therapy instead of a conventional dressing?

Clinical experience with maggots has shown that they can clean wounds in a fraction of the time taken by more conventional dressings, which could potentially speed up healing times. They are also useful in the management of infected wounds containing bacteria that are difficult to kill with more conventional treatments. Maggot therapy has also been shown to be successful at eliminating MRSA from wounds.

What is the ethical position relating to the use of maggots?

The use of maggots in wound management has a sound basis in literature. It appears to be free of any serious or significant side effects and can have major advantages over conventional treatments for certain types of wounds. If a specific patient has no objection to the use of maggots there appear to be no ethical barriers to their use.