Warts or verruca are a common problem affecting the foot. Warts / verruca usually present on the plantar (bottom) aspect of the foot or on the sides of the toes.
A blood borne virus called the human papilloma virus (HPV) causes warts/verruca. The two most common strains of this virus that cause warts / verruca are the HPV 2 and the HPV 4. These are DNA viruses. The virus finds its way into the body via a site of trauma and then becomes parasitic to a single skin cell called keratinocytes. The wart virus then causes the skin cells to mutate and grow. This virus thus manifests itself in a verrucous tumour that we commonly know as a wart.
The appearance of warts is usually soft, white spongy lesions that will break into pinprick haemorrhages when traumatised. Some warts on the sole of the foot are covered by callus or hard skin which offers it increasing protection and a place to “settle in”. Their appearances vary depending what type of wart you have.
The main difference between warts on the soles of the feet and warts in other locations of the body is the pressure associated with standing on the wart causes the wart to grow inwards instead of outwards.
Diagnosis of a wart is usually made on their physical appearance or if there is a substantial amount of callus tissue covering the wart this is debrided and then examined. One simple diagnostic test for a wart it to apply lateral pressure to the wart (pinch it). If there is a sharp stabbing pain the lesion is most likely a wart.
There are many options to consider when treating plantar warts. Usually the treatment will consist of your podiatrist debriding any dead skin that may be covering the wart. Then the podiatrist may apply some type of caustic or acid (strong keratolytic preparation usually salicylic acid or silver nitrate). This process will be repeated approximately once per week until the wart is removed.
Other options such as freezing (cryotherapy), burning (electrocautery) or surgical removal (curretage) of the wart are also available. The type of treatment will depend greatly on the patient and the area of the body that the warts will affect.