What is a verruca and what causes it?

A verruca is a viral infection which affects the outer layer of skin (epidermis). It’s the same type of infection that causes warts. The viral infection can enter the skin if there is any break in the skin or if the skin is very moist – which explains why people believe they pick them up at swimming pools. Patients who are immunocompromised due to either certain medical conditions or medications are more susceptible to verrucae.

Symptoms of verrucae

Verrucae develop on the feet (often the soles) and toes. They tend to be flat rather than raised but can be painful if they’re on a weight-bearing part of the foot.

Verrucae are generally well defined as they become encapsulated within the outer layer of skin on the foot. As a result, the natural skin lines that you can see on the skin are ‘pushed’ around the verruca which is one of the diagnostic features.

The infection targets the layer of cells that produce new skin cells and as a result, they often form hard skin quite quickly over the top, particularly when they are on the sole of the foot. The pressure from the extra cells pushes blood vessels close to the skin which is why you often see little black dots.

How can I prevent getting verrucae?

Unfortunately, there have been no studies to show how you can 100% prevent getting a verruca, but I have listed some simple tips below:

  • take care of your feet – keep them clean and dry, change your socks every day and don’t go barefoot in public places
  • avoid touching other people’s warts or verrucae
  • avoid sharing towels, flannels, shoes or socks with other people
  • wear sandals when in community showers and on the side of a swimming pool (however, there is little protection you can take once in a swimming pool)
  • make sure you don’t have any obvious breaks in the skin in case you are exposed to the virus.

Treatment for verrucae

Many verrucae are painless and they will resolve of their own accord but this can take several years.

There are a range of treatment options available for verrucae including:

  • topical acids and homoeopathic treatments
  • topical anti-viral ointments
  • cryotherapy (freezing with liquid nitrogen)
  • needling
  • electrosurgery
  • Swift therapy