As there is a vast array of misinformation and varying opinions regarding treatment it is worth explaining some common questions and misconceptions.
What is a verruca?
Verruca is the term used for tumors of the human papiloma virus (HPV) when they occur on feet (called warts when on other areas of the body) They can infect any area of skin but are most common on feet and hands as they are contact areas allowing passing of the infection. They do not have roots as such but are self contained lumps of infected skin cells. They live only in the epidermis (outermost layers of skin).
How do i identify one?
They are not always painful though some are and they do not have to have visible black spots in them though some do. On a young child any spot or lump on the foot is most likely a verruca. On an older child or adult it could be a verruca, a corn or callus. Corns are more often circular lumps and painful to press inward, verrucae can be irregular shaped and painful if squeezed from the sides. Callus is a thickening of the outer layer of skin, it is semi clear allowing the [fingerprint] lines in the skin to be visible throughout the area while verrucae tend to have a cauliflower like appearance with the skin lines diverging around it.
How did i catch it?
As far as anyone knows they can be spread any place where people are barefoot. It is sometimes claimed that they only spread where the floor is wet but it is more likely that wet skin only makes it more likely to spread, it is not essential. There is actually no evidence that for example your child is safe from infection doing barefoot gym.
Why have I been told by my GP / pharmacist / other podiatrist not to treat my verruca?
It is now the case that almost every NHS provider does not treat verruca. This has gradually become the norm over the last decade and the usual cited reason is an opinion stated in the British Journal or Dermatology (link at bottom of page) that non-treatment is a valid treatment option: "No treatment has a very high success rate
(average 60±70% clearance in 3 months)". If you are reading this it is likely you have already tried not treating it for 3 months and this method has not worked for you. The authors do not claim all verrucae resolve on their own and the paper goes on to describe a number of other valid treatment options for more persistent verrucae.
Another reason some advise to not treat is that many practitioners believe all verrucae have a maximum life of (variously quoted) 2 years up to 7 years. This is not bourne out by the experience of this podiatrist who regularly sees patients who claim to have had their verrucae for 10 or even 20 years and only then seek treatment because they start spreading or hurting.
So should i get them treated?
It really is down to the patient or parent to decide this, but not treating it is a gamble. To start with they are usually pain free and small enough to ignore so this is when they are usually left alone, they might go on their own but if they don't it is a huge shame they weren't treated as that was also the time they would have been easiest to cure.
They are contagious, so the risk with waiting is that in the meantime they can spread to other areas of the body and other people. It is not uncommon to see most of a family being infected before treatment is begun and it is very common to see people who knew they were infected with just one small verruca and while hoping it will go on it's own have given it the chance to spread and they then have 10 or 20 which is much more difficult and expensive to treat.
Another reason to treat early is that even a single verruca is much more difficult to treat if it has been allowed time to grow. This is less of an issue for warts on hands as they grow outward from the skin, however a verruca on the sole of the foot will get pushed deeper into the skin, gathering blood supply from the surrounding tissue. The deeper they are the more difficult it is to apply sufficient treatment to destroy it without damaging surrounding tissue and treatments therefore tend to be more painful and less successful for older verrucae.
Should i try the home treatments available from the pharmacist first?
The advertisements for home verruca kits invariably claim it will be easy and quick to cure your verruca. Surprisingly most people don't take the kit back for a refund when it doesn't work so it is hard to get statistics for how far from true the claims are. Nearly all patients who attend the clinic have tried a few or sometimes all of the treatments available and none have worked. From the point of view of an experienced podiatrist looking at what is in the kits and considering how hard it can be with much stronger methods, none seem likely to work. It may well be that the successful cases are those verrucae already mentioned that would have gone without treatment anyway.
A big problem with the home kits is removing what has been destroyed between applications. The file that comes with them is supposed to be used for this but it is obvious where a verruca is pushed inwards a flat file is never going to be able to remove it. The only way to remove it sufficiently is with a scalpel (which is not painful) and this can only be done by a podiatrist. It is also often the case that verrucae are covered by a layer of callus which presents a barrier for salicylic acid and freezing treatments and this also can only be fully removed by a podiatrist.
Might duct tape work?
It is becoming very common to hear of patients being advised to try duct tape (or duck tape / gaffer tape) so it is worth explaining the history of this treatment and why it is unlikely to work for verrucae. Anecdotal evidence for it seems to have originated from the army where soldiers are trained to inspect their feet every day and therefore will notice a verruca in it's early stages. Applying any occlusive (water-tight) tape will macerate (waterlog) the tissue causing superficial destruction so that the top layer of skin can be peeled off (very much like the top of a blister) taking the superficial new verruca with it. A small study was then performed which showed that using duct tape was a little more effective than cryotherapy (freezing) but crucially the majority of subjects were children with warts on their hands. Unfortunately this study of 50 children has been widely misinterpreted and used as evidence that duct tape is also likely to work for any verrucae. Two later studies on adults and children have since shown that it does not usually work on feet but these have been widely ignored (links below). Salicylic acid treatments (and banana skin) work in a very similar way by water-logging the tissue and on older verruca even high doses of high strength acid is rarely effective so tape alone really has no chance of working.
So to sum up, what is your advice?
If you or your over 5 year old child have a very new verruca, no more than a few millimeter in diameter and that doesn't feel at all like a hard lump, it is still worth trying a salicylic acid home treatment in combination with a waterproof tape for a short time. Apply the acid following the instructions that came with it (though ignore where it might say there is no need to cover it), then cut a piece of any waterproof plastic tape just a little bigger then the verruca and cover it, holding that tape in place with a non-waterproof white medical tape (Mefix/Hypafix/Micropore etc). Leave it on for up to a week, if you think it has moved re-apply in the correct place, do not let the skin dry out between applications. You are aiming to make the skin just around the verruca turn brilliant white at which time it might come off when you remove the tape or it will come off like the top of a blister. If the verruca has gone you should see no disruption of the lines in the skin. If after a few weeks trying, or if after you have successfully made the skin turn white and have removed the top layer, it has still not gone, or before that if there is any redness of the skin or pain, seek professional help before it gets any bigger or spreads.
If you or your child have verrucae more than a few millimeters diameter, if it feels lumpy or there are more than one of them it is too late to expect tape or any of the pharmacist treatments to work. It is best to seek professional help.
The clinic offers a combination of chemical treatments and cryotherapy (freezing) and this will be explained for you before any treatment begins. Which one is most suitable depends on a number of things and is decided based on the experience of the podiatrist and what suits the number, location and duration of the verrucae.
Link to "no treatment paper" -
- Sterling, J.C., Handfield-Jones, S. and Hudson, P.M. (2001 ) Guidelines for the management of cutaneous warts. British Journal of Dermatology 144(1), 4-11 [full paper]
Links to tape studies -
- Focht DR 3rd, Spicer C, FairchokMP; The efficacy of duct tape vs cryotherapy in the treatment of verruca vulgaris (the common wart). Arch Pediatr Adolesc Med. 2002 Oct;156(10):971-4. [abstract] [full paper]
- Wenner R, Askari SK, Cham PM, et al; Duct tape for the treatment of common warts in adults: a double-blind randomized controlled trial. Arch Dermatol. 2007 Mar;143(3):309-13. [abstract]
- de Haen M, Spigt MG, van Uden CJ, et al; Efficacy of duct tape vs placebo in the treatment of verruca vulgaris (warts) in primary school children. Arch Pediatr Adolesc Med. 2006 Nov;160(11):1121-5. [abstract]