Viral warts are caused by the human papillomavirus and are very common particularly in childhood, occurring in almost 50 per cent of children at some time, but after peaking in adolescence, they tend to become less common. In general, the hands and feet are most commonly affected and the appearance depends on the exact location on the skin. In healthy children, warts tend to resolve without any need for treatment. However, in individuals whose immune system is compromised, warts may be persistent, despite treatment, and may become widespread.
Warts may manifest on the skin in different ways:
1. Common warts begin as smooth flesh-coloured flat area that enlarge and stick out from the skin with a characteristic surface of rough and thickened keratin. Since this is a skin infection, such warts may occur at sites of injury.
2. Plantar warts (verrucae) are similar and occur on the soles of the feet where they can be very painful. Such warts only protrude very slightly from the surface of the skin and may mimic a foreign body.
3. Mosaic warts are collections of small and densely packed individual warts. Because of their density on the skin, they may be resistant to treatments.
4. Plane warts are found over the face, arms and legs and are flat topped.
5. Periungal warts are found around fingernails or toenails.
Since they are caused by a virus, warts are contagious and spread from person to person by direct contact with warts, or by touching contaminated objects, such as towels, etc. Warts may also spread to other parts of the body by touching or scratching existing warts. It is therefore helpful to keep bites, scrapes and rashes clean and covered, and to wear shoes or sandals in all public places.
Some warts may persist and become large and painful, requiring treatment. Treatment may also be sought by the child or by the parents for cosmetic reason.
Salicylic acid applied locally as a cream or an ointment is helpful.
Cryotherapy may also be used and this uses a freezing agent to produce small burns in the skin. However, cryotherapy may cause pain, swelling and blistering and too aggressive treatment may cause scarring.

Source: Weekender, February 21, 2009