There has been increasing interest in use of maggots in wound healing
Maggots may not have the miracle healing properties that have been claimed, a UK study suggests.
Researchers comparing maggots with a standard "hydrogel" in treating leg ulcers found little difference.
Recent excitement over using maggots to speed up healing and even reduce MRSA infections in leg ulcers seems to have been premature, they said.
The British Medical Journal study is the first to compare maggots with standard treatment.
Leg ulcers can be very difficult to treat and after use of high-compression bandages only about half are healed within 16 weeks.
One common treatment is to use a water-based gel to keep the wound moist and promote the natural healing process.
Maggots, or larval therapy, are another option - but it can be more tricky to place them in the wound and they have to be specially ordered which takes a few days.
The theory has been that maggots are effective because they "clean out" dead tissue - a process called debridement - stimulating healing and getting rid of bugs such as MRSA in the process.
But although larval therapy is being used more and more, it has only been tested in one randomised controlled trial of 12 patients, the team said.
In the latest study, 270 patients with leg ulcers from around the UK were treated either with maggots or hydrogel and progress followed for up to a year.
There was no significant difference in the time it took the ulcer to heal between the two treatments or in quality of life.
Maggots were not more effective than hydrogel treatment at reducing the amount of bacteria present or in getting rid of MRSA and were, on average, associated with more pain.
The only benefit seemed to be that the dead tissue in the wound was cleaned out more quickly
A separate study looking at cost-effectiveness estimated there was little to choose between the two therapies.
Study leader Professor Nicky Cullum, deputy head of health sciences at the University of York, said the resurgence in interest in using maggots had been "premature".
"The ulcers treated with larval therapy did get cleaner - which is not surprising as they're an active debriding agent - but that rapid cleaning did not lead to rapid healing."
She said it would be up to clinicians to decide which was the most appropriate for their patients, but in general there was no extra benefit from maggots over standard therapy.
"It comes down to the aim of treatment. If for some reason rapid debridement is important, then you would choose larval therapy - for example if someone was having a skin graft.
"This will help them make more informed decisions."