Verrucas, also known as plantar warts, are warts that occur on the soles of feet and are particularly common in kids.
Verrucas are flat with thick skin and their hard edge is usually accompanied by a soft centre. You might even notice a tiny black spot in the centre – this is harmless and is simply bleeding bought on by pressure caused by walking and standing.
They are the same as other warts on the body but may be painful due to their positioning on the foot. They are extremely contagious and are commonly associated with swimming pools because people pick them up from walking around bare foot.
It can take a few months for them to develop so make sure your little one wears flip flops or swim socks around the swimming pool to prevent them catching the virus.
While not pleasant to look at, verrucas are harmless and usually go away without any intervention. However, they can spread across the foot and while it is not necessary to have them removed, you may find that the positioning of the wart is in a sensitive area and is causing your youngster pain.
Waiting for a verruca to go away on its own is perfectly fine, if it is not causing your youngster any problems; however, it can take between 10 weeks and two years for them to be fully gone. If you do want your child’s verruca removed there are various treatment options available, although some can be time consuming and sore. The most commonly used treatments are using salicylic acid or freezing them off.
If you decide to use salicylic acid you will need to apply it every day for up to three months. The acid burns the top layer off so you will need to remove the dead tissue every couple of days. To freeze a verruca off, a doctor or nurse will spray or apply liquid nitrogen onto the affected area.  While it is the most effective and quickest method, it can be quite painful and there is the risk of scarring. Bear in mind that they can return even after treatment.  
If your little one does have a verruca make sure it is covered while they are taking part in activities that require them to remove their shoes, particularly around a swimming pool where they can spread very quickly.