Plantar Warts: What is the best way to tackle these stubborn lesions?

As the weather warms and we move into spring and summer, many head back outside for outdoor recreation.  As people increasingly walk outside barefoot, across pool decks, in the yard, or in public areas, the risk of developing plantar warts increase.  Unlike other areas of the body, warts on the plantar aspect of the foot can be especially challenging to treat due to the thickness of the plantar skin.  Typical over-the-counter treatments are less effective.  

What are plantar warts?

Plantar warts are a viral infection of the superficial layers of the skin.  Caused by different strains of the HPV virus, the virus propagates between the epidermal and dermal layers of the plantar foot, away from the body’s immune system detection.  The wart itself is non-cancerous, however warts can cause significant callusing and pain with weightbearing on the area.  They often first appear as a small, circular callus with characteristic small, black spots within the callus.  Warts can spread from the initial lesion into clusters of warts called mosaic warts.  It is advised to have any plantar skin lesion examined by a doctor because there are a wide variety of skin lesions that can appear on the foot and can be mis-diagnosed as a wart.  

How are plantar warts treated?

As mentioned above, plantar warts are more challenging to treat than warts on other areas of the body due to the thicker plantar skin surface.  Traditional over the counter wart treatments you can buy at the drug store are often not potent enough to fully resolve the wart.  Furthermore, traditional treatments like liquid nitrogen are less effective on the foot as they often don’t allow for enough penetrance to remove the entirety of the wart.  There are a variety of more effective treatment options, however.  Prescription strength compound wart cream can be effective, and is typically applied daily at home, with intermittent doctor visits to debride the significant callusing that will develop with use of these creams.  Perhaps the most common treatment used in our office is triple acid solution with cantharidin.  Cantharidin is a poison from a beetle species that causes a severe blistering reaction when applied to the skin.  This allows the epidermal and dermal layers to separate, and the acid in the solution effectively kills the virus.  These treatments are typically done every 2 weeks, with high effectiveness rates while remaining relatively non-invasive.  Other options are typically saved for cases where the previous options fail.  Surgical excision with a hyfrecator, or treatment with a Candela laser have both shown to be effective treatments.  However, these options leave you with a wound where the wart was, and this needs to be appropriately offloaded and allowed to heal.  

Tips to avoid plantar warts:

• Avoid walking barefoot in public, highly tracked areas (showers, pools, water parks, etc)
• Change shoes and socks daily and avoid sharing shoes and socks
• Don’t touch warts on other people
• Avoid scratching warts, this can lead to spread
• Keep feet clean and dry

If you note a suspicious lesion on your feet, call our office to schedule an appointment to get them addressed prior to them spreading!

Author

Dr. Evan Smith Dr. Evan Smith is a Board-Qualified foot and ankle surgeon, providing personalized, high-quality care to the Castle Rock community as a physician with Castle Rock Foot & Ankle Care. Dr. Smith received a Bachelor of Science degree in Biology from Illinois Wesleyan University. He then went on to earn a Doctor of Podiatric Medicine degree at Des Moines University College of Podiatric Medicine and Surgery in Des Moines, Iowa, where he received The American Board of Podiatric Medicine Graduate Merit Award. Following medical school, he completed a three-year foot and ankle surgical residency program at Legacy Health in Portland, Oregon, gaining comprehensive training in all aspects of foot and ankle surgery. Dr. Smith takes pride in connecting with his patients and providing personalized care to get patients back to the activities they love.