Plantar warts, also known as verrucas, are thick, rough callus-like lesions that occur on the sole of the foot. Warts can occur on their own (ie. solitary), or in clusters (ie. mosaic). Verrucas can be seen in all age groups but are particularly common in children and the elderly. When on weight bearing areas, they can become quite uncomfortable when pressure is applied while standing, walking or running.
Warts are caused by different strains of the human papillomavirus (HPV). HPV is a very common virus and it is probable that you have or will contract some form of it in your lifetime. Interestingly, each person’s immune system responds differently to the virus, so not everyone who comes in contact with it develops warts. Plantar warts are contagious, and can easily be transmissible through indirect contact. It can simply take a minor break in the skin for the virus to enter our body. The virus thrives in warm and moist environments. This makes it particularly common for it to spread in communal areas such as swimming pools, gyms and saunas, where people love to walk barefoot.
While anybody can develop a plantar wart, they are more likely to affect:
– Children and teenagers, due to their developing immune system
– People with weakened immune systems (eg. those who are undergoing chemotherapy, are HIV positive, received organ transplants)
– People who have had a history of plantar warts
Plantar warts are usually able to be diagnosed clinically. Often warts can be confused with corns due to their similar appearance. However, unlike corns, warts are generally painful to squeeze on the sides, have no skin lines running through them, and have small black dots in the centre which are the capillaries. A podiatrist may scrape the dead skin overlying the wart which can cause pinpoint bleeding, another indication of a wart.
If cases where diagnosis is difficult, a biopsy can be taken and sent for pathology to determine whether the tissue is positive for HPV.
How to treat plantar warts
Plantar warts may resolve without any treatment as the immune system does all the hard work in clearing the wart. It can however, take a while for our body to recognise its presence and stimulate a response. In children, 50% of warts disappear spontaneously within six months, and 90% are gone in 2 years. Unfortunately, verrucas are more persistent in adults. If the verruca is painful, bothersome or starting to spread, it is important to have it treated.
There are several ways to treat a wart. A few of the modalities we use at Erko Podiatry are outlined below.
– Cryotherapy: Involves freezing a wart using a very cold substance (usually liquid nitrogen)
– Chemocautery: Involves debriding (removing) the dead, non-viable skin to expose the tissue, and applying a keratolytic agent (usually salicylic acid) over the wart. A dressing and padding is then applied to protect the area. As a rough guide at least 4 treatments are required for small warts however with large or multiple warts it can take longer
– SWIFT therapy: Swift uses microwave energy which is delivered through a special probe applied to the skin to treat the affected tissue. This process creates an immune response in the tissue and leads to elimination of the wart through the body’s own defence mechanisms. This process usually requires 3-4 treatments and requires no dressings.
The HPV stays in the body for the rest of your life and therefore warts can return at any time, anywhere on the body. It is not uncommon for them to return to the same place as previous warts. They are more likely to recur in patients that are immunocompromised, or frequent smokers.
Once you have a wart there is a chance it can come back. You can certainly reduce the risk of contact by wearing shoes especially in areas where people regularly walk barefoot (eg. swimming pools and locker rooms). If you live with someone who has warts, it’s best to avoid going barefoot in spaces you share with them.
Over the counter treatments from the chemist normally have a smaller percentage of salicylic acid, however they can actually do more harm than good. If not applied correctly, the acid can burn the surrounding healthy tissue causing unnecessary pain, and may even result in an open wound or infection. These treatments are especially dangerous for people with reduced feeling or blood flow to their feet. If you are pregnant, immunocompromised, or have a condition affecting the nerves or circulation in the feet (eg. diabetes) you should never try these treatments at home.