A plantar wart is a small, rough growth caused by a viral infection (Human Papillomavirus or HPV) that develops on the sole of the foot, typically on weight-bearing areas. Pressure from walking often forces the wart to grow inward beneath a layer of thickened skin. After a wart diagnosis, the immediate concern is often whether personal items, like shoes, are contaminated and require disposal. Fortunately, throwing away footwear is generally unnecessary, as simple sanitation steps can effectively reduce the risk of re-infection.
The Cause of Warts and Transmission
Warts are caused by certain strains of the Human Papillomavirus (HPV), a slow-growing virus that infects the outer layer of the skin. The virus enters the body through tiny cuts or breaks on the bottom of the foot. Once inside, HPV attacks the skin cells, causing them to grow rapidly and form the characteristic rough lesion.
Transmission occurs through direct contact or indirectly through contaminated surfaces. The virus thrives in warm, moist environments, making communal areas like public showers and locker rooms common places for exposure. When an infected foot sheds viral particles onto a surface, those particles can remain viable and potentially cause a new infection if they encounter another foot with broken skin.
Risk Assessment for Contamination in Footwear
The risk of re-infection from footwear is low compared to the risk of the virus spreading to other areas of the same foot, a process known as autoinoculation. While HPV is resistant to heat and drying, its infectivity is significantly reduced when dried out. The virus struggles to remain viable for long periods on dry, porous surfaces like the lining of a shoe.
Viral particles can survive on inanimate objects, or fomites, including the interior of shoes. Studies show that HPV can be detectable on surfaces for several days, but the infectious potential drops dramatically upon desiccation. Therefore, the likelihood of contracting a new wart from a shoe that has been left to dry is minimal. Discarding shoes is an overreaction, as proper sanitation effectively mitigates the viral load.
Practical Steps for Shoe Sanitation
To prevent recurrence or spread, the most effective step is ensuring the shoe environment remains dry, as moisture provides ideal conditions for HPV to thrive. It is helpful to rotate footwear so that shoes have 24 to 48 hours to air out and dry completely between uses. This rotation naturally reduces the viral load by exposing the shoe lining to desiccation.
Disinfecting sprays are recommended to further reduce the viral presence inside the shoe. Use an antimicrobial spray designed for footwear or a general disinfectant certified to kill viruses to target remaining particles. For maximum effect, look for products containing hypochlorite, which is shown to be effective against HPV. Routine changing of socks and wearing clean, breathable socks also limits the transfer of viral particles and moisture into the shoe.