Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. One possible treatment involves the use of a laser and a new Cochrane Review of the evidence was published in September 2022. We asked one of the authors, Ana Carolina Nunes from Cochrane Brazil in Sao Paolo, to tell us more in this podcast.

Ana: Hypertrophic and keloid scars are raised and bumpy scars that form when a wound does not heal correctly. They can be discoloured or reddened, and can cause pain and itching. A range of treatments are available, including silicone gels and steroids, with laser therapy being an alternative.
During laser therapy, areas of skin are targeted by a powerful beam of light which can break down damaged tissue. Different types of laser therapy are available depending on the patient's skin type and the nature of the scar. However, it is expensive and has potentially harmful side effects, so it's important to establish whether it's safe and effective, which is why we did this Cochrane review.
We investigated whether laser therapy is an effective treatment for people with hypertrophic and keloid scars, based on 15 studies, involving just over 600 participants, including children and adults of both sexes.
In these studies, which lasted from 12 weeks to 12 months, different kinds of laser devices were compared with no treatment or with other types of treatment. Laser therapy combined with another treatment was also compared with that treatment alone. Coupled with this complex mix of study designs, the studies also had small number of participants, limitations in their methodology and conflicting results.
Unfortunately, this means that the currently available evidence is insufficient to be sure whether laser therapy alone or combined with other treatments makes hypertrophic or keloid scars less severe than no treatment or other treatments. Some side effects of laser treatment were also reported, including damage to the skin or underlying blood vessels, redness and numbness; but we can't be sure how common these side effects are.
Taken together, the results of the 15 studies we identified do not allow us to determine if using any kind of laser therapy is more or less effective than other available treatment for hypertrophic and keloid scars. We also cannot be sure whether any type of laser therapy leads to more harm than benefit when compared with no treatment or other treatments. Resolving this uncertainty and guidance for future clinical practice will require further high‐quality trials, with long‐term follow‐up and data on the rate of scar recurrence.

Mike: If you would like to learn more about the existing studies and watch for an update of the review if those additional trials become available, you can find it online at Cochrane Library dot com with a simple search for 'Laser therapy for scars'.