The Cochrane Skin Group has prepared nearly 90 full reviews of the effects of interventions for a wide range of skin conditions. One of these was updated for the third time in May 2017, to present the latest evidence on the viral infection, molluscum contagiosum. The lead author, Hans van der Wouden, from the Amsterdam Public Health Research Institute in the Netherlands, describes the latest findings in this podcast.
John: Hello, I'm John Hilton, editor of the Cochrane Editorial unit. The Cochrane Skin Group has prepared nearly 90 full reviews of the effects of interventions for a wide range of skin conditions. One of these was updated for the third time in May 2017, to present the latest evidence on the viral infection, molluscum contagiosum. The lead author, Hans van der Wouden, from the Amsterdam Public Health Research Institute in the Netherlands, describes the latest findings in this podcast.
Hans: Molluscum contagiosum is a very common skin infection, caused by the molluscum virus. It affects people worldwide but is mainly seen in children. It usually presents as single or multiple shiny, skin coloured or pink pimples of a few millimetres in diameter, with a little indentation at the top. The pimples are filled with white cheesy material where the virus lives.
In healthy people the mollusca spots go away of their own accord, although this may take several months to over a year. However, some seek treatment for cosmetic reasons or because of concerns about the condition spreading to other parts of the body or to others. Treatment is intended to speed up the natural healing process.
Disappointingly, our Cochrane Review continues to show that there is a lack of reliable evidence to support these interventions.
We reviewed the evidence on the effects of any treatment for molluscum contagiosum, but excluded studies in people with a suppressed immune system and in those who got infected through sexual transmission.
We have now found 22 randomized trials, with a total of 1650 participants. Twenty studies evaluated topical treatment, such as the use of a cream or physical destruction of the lesions. The other two studies tested oral treatment.
Patients in the trials were followed for variable lengths of time: from only 3 weeks to over half a year, but only 5 of the 22 studies had a follow-up longer than 3 months. This is a shame because adequate follow-up is important for evaluating the healing process and to monitor whether new lesions continue to appear.
Our main finding is that the many common treatments for molluscum have not been evaluated enough. For example, popular types of physical destruction like curettage and cryotherapy have only been evaluated in a few small studies of low methodological quality.
While, on the other hand, the three large unpublished studies that we found of one treatment option, topical imiquimod, had included a total of more than 800 participants but showed consistently that the drug was no more effective than placebo, and had more side effects in terms of application site reactions.
The consequence of this disappointing evidence base is that none of the treatments can be recommended as being backed by good evidence. Therefore, just waiting for the spots to go away on their own accord remains one of the best ways for dealing with this infection.
With that in mind, our main conclusion is that high quality, adequately powered studies of long duration are needed, which should focus on commonly used treatment options and test these against placebo.
John: If you would like to read about the research that has been done, and watch for future updates if these new trials are done, you can find the review online at Cochrane Library dot com. Just go to the website and search 'molluscum'.