Warts are infections of the skin caused by the human papillomavirus (HPV). There are many different types of warts, and they have an affinity for certain regions of the body. Common and plantar warts are especially common in children, with around one in five children affected.

Common warts

Common warts occur most frequently on the hands and knees, although any body part can be affected. They present as hard, raised lumps with a rough surface and can occur singly or in clusters.

Plantar warts

Plantar warts appear as small, hard bumps with tiny black dots on the surface. They most commonly occur on the sole of the foot, in weight bearing areas. This constant pressure causes restriction of the outward growth of the wart, and instead it grows inwards. The pressure on these nerves can cause pain on walking.

Risk factors

  • Direct contact with other warts
  • Nail biting
  • Injuries to the skin or frequent skin infections
  • Swimming in public swimming pools

Lifestyle advice

  • Avoid direct contact with warts
  • Don’t pick warts. This can contribute to spreading the virus
  • Use a disposable emery board or pumice stone specifically on warts. Do not use the same one on healthy skin and nails
  • Don’t bite nails
  • Be careful when grooming and shaving in areas where there are warts. Broken skin in these areas can spread the virus.


In most cases, warts will resolve themselves within a few years without treatment. There are however, some topical over-the-counter treatments at your local pharmacy that can be effective in removing common warts.

Salicylic acid

Topical treatments containing salicylic acid alone, or in combination with lactic acid, are designed to shed topical layers of skin. It requires many weeks of treatment, and compliance is essential to increase the chance of success of the treatment. For best results it is recommended to soak the wart in warm water for a few minutes before filing with an emery board and pumice stone to remove any dead skin cells. The product (solution, gel or stick) should then be applied daily to the affected area only, as application to the healthy skin may cause irritation, discolouration or scarring. You can apply clear nail polish to the healthy skin around the wart to protect it from the treatment. Soaking, filing and application of the product must be repeated daily.


Freezing therapy involves applying liquid nitrogen to the wart. While this was traditionally done in a doctor’s office, there are now a number of over the counter liquid nitrogen products available at your local pharmacy that you can apply at home. The applicator or device is applied to the wart for 20 seconds, causing a blister to form around and under the wart. Often only one application is required, but in some persistent cases the treatment may need to be repeated.

Common side effects of cryotherapy may include pain, blistering and discolouration of the skin. It is for this reason that it is not usually recommended as first line treatment, particularly in children.