Verrucas, which are warts on the feet, are infectious lumps that also crop up on the hands, and occur in about 5% of children. They are caused by a type of human papilloma virus that enters through direct contact with the skin. Children and teenagers are most at risk but some people seem to be more susceptible than others.
Although not terribly contagious, the virus thrives in moist, warm conditions, which is why infections are rife in swimming pool changing rooms. Children hate them, especially the fleshy finger variety that no one wants to hold hands with in the playground, picking or biting them so they bleed, and encouraging them to spread. Verrucas are small, grainier growths on the soles of your feet, although they can also be fleshy depending on where they are. They are round, often white and have a black dot in the middle (from a blood vessel). Warts don't usually hurt (except for those emotional scars), but if they grow on weight-bearing sites on the feet they can be tender and painful when you stand or walk.
The great thing about warts is that whatever you do they usually go away by themselves – unless you have an underlying condition that affects your immune system. The bad thing is that it takes time for them to disappear. Three out of 10 warts will go on their own in 10 weeks. Within two years, two-thirds of all warts will go without treatment. But if you've still got them after two years they are less likely to go on their own. Warts seem to last longer in older children and adults.
If treatment was easy and effective, then no one would wait to get rid of a wart. But the cure can be worse than the condition: any treatment will irritate the healthy skin around it. You can buy topical preparations, containing salicylic acid (paint, ointment, gels) over the counter, but you must apply these for 12 weeks every day. You should soften the skin by soaking in warm water and then use a pumice stone or nail file (don't let others use it afterwards), to rub off the top of the wart before applying. It's thought to work by causing local irritation, and stimulating the immune system to attack the virus. It gets rid of up to eight out of 10 warts within three months.
Some people use the duct-tape method, which involves covering the wart for six days at a time, rubbing off the top of the wart by soaking in warm water and using a pumice stone or nail file before applying new tape. It is thought the process also stimulates the immune system. Seven in 10 warts will be gone within two months.
Freezing warts off with cryotherapy, often using liquid nitrogen, is a drastic option and there isn't good evidence that it works better than salicylic acid. You have to have around four lots of cryotherapy – each one a few weeks apart. It is applied on a cotton bud or using a spray and can cause burning and blistering, especially during the treatment. If it's not working after three months then it's unlikely to work at all.
Why not just cut them out, you may ask? Because the warts often grow back.
If you are not sure your wart is really a wart, or if you have diabetes, a compromised immune system or are pregnant, then see your doctor before trying to get rid of them.
You don't need to restrict swimming, although flip flops in the changing room is a good idea. When I have had warts, I've left them and they have magically disappeared. I let my daughter try cryotherapy because she hated hers, and although she screamed at the time, they all vanished within three weeks.