Recently, a patient came in to the office after months of pain from a round, thickened area of skin on the bottom of her foot. The patient was sure it was a callus and was confused as to why it was not going away. The lesion showed up out of nowhere in an area that she never had a problem with before. She could barely stand on her foot due to the pain, and any type of activity has become very uncomfortable.
If you find that a painful lesion randomly shows up on the bottom of your foot where there never was one before, it may not be a callus at all. It may actually be something that is often confused with a callus, such as a plantar wart. While calluses are caused by excessive pressure beneath a bone on the foot, warts are caused by a virus. You have to come in contact with the virus. You literally have to step on it, where it gets into the skin and causes the skin to grow abnormally. Anywhere you’re walking barefoot is fair game for picking up the virus; pools, locker rooms, hotel rooms, even the security line at airports!
Warts on the bottom of the foot are also known as plantar verrucae. Warts affect 7-10% of the population and can show up as a singular lesion or in multiple lesion patterns. The dark and moist area within a shoe is the perfect environment to facilitate survival of the virus. It is caused by the human papilloma virus and can be very painful, especially on the bottom of the foot, if you’re bearing weight directly on the lesion.
Appearances often help a physician distinguish between a callus and a wart. In a callus the normal skin lines continue through the lesion, however with a wart the lines will diverge around the lesion. The margins, or borders, of a wart are usually very distinct whereas in a callus the margins tend to be more. A wart also consists of little dark dots, which are actually small blood vessels that develop to provide nutrients to the wart. If trimmed, the lesion can bleed vigorously. Calluses, on the other hand, have no direct blood supply.
Skin lines go around the lesion
Clearly defined Margins
Multiple dark dots within lesion
Can occur anywhere on the foot
Skin lines go through the lesion
Unclear/diffuse marginsNo blood supply in lesion
Always in weight bearing areas
Warts tend to spread and are unlikely to go away on their own without treatment. Treatment options include topical medications, laser, excision, freezing, or a combination of modalities.
The above treatments won’t work for calluses. So, if you have any type of skin lesion on your foot, especially one that is painful or new, let the experts at Kansas City Foot and Ankle diagnose your condition and treat it quickly and appropriately.