A plantar wart is caused by coming in contact with a HPV skin virus and is most commonly seen on the bottom or plantar aspect of the foot. It usually presents as a calloused, or thick flesh colored lesion that when seen up close may have what textbooks refer to as a “cauliflower” appearance. When they are in a cluster they are called “mosaic” warts. These tend to be more difficult to treat and usually need to be addressed more aggressively.
Plantar warts are contagious and can spread to other people or to multiple areas of the feet, like the top of the foot and to the toes. They tend to become painful, larger and deeper if they are left untreated for extended periods of time. Plantar warts can look like and mimic many other skin lesions, making the diagnosis a bit more difficult. Patients often mistake a wart for a splinter or a callous. Plantars wart can differ from calluses based on pressure responses to the lesion. Plantar warts tend to be painful when applying pressure from either side of the lesion while calluses tend to be painful when applying direct pressure.
An experienced podiatrist can spot clinical signs of a wart and make a diagnosis. Some of these include “pinpoint bleeding” and loss of “skin lines”. When looking at a wart with the naked eye, there is often small little dark dots within it. These darkened dots are tiny hemorrhages or (bloodclots) under the skin. The wart has it’s own blood supply which feeds the wart. This pin-point bleeding may be noted when the wart is shaved down or scratched. This pinpoint bleeding is characteristic and unique to plantar warts versus other lesions or calluses which are not viral. Loss of skin lines leading to and away from the wart is another unique characteristic of warty lesions.
Most times the diagnosis is made clinically and by visual examination of your podiatrist. After proper diagnosis some common treatments for warts include: cryotherapy, acid treatments, topical medications, excision and laser therapy.
If common treatments are failing to resolve the wart, a skin biopsy is sometimes warranted to get confirmation on the diagnosis and further rule out other pathology. In rare cases warts can be precancerous. A skin biopsy is a simple procedure and is routinely done in the office setting using a local anesthetic. The skin is prepped and cleaned with an antiseptic solution, the local anesthetic is injected, and a section of lesion is removed. The area is then bandaged and local wound care instructions are given to the patient. The skin specimen is then sent to a pathology laboratory for microscopic evaluation by a specialist called a dermatopathologist. Results of skin biopsies can be expected in about a week. Adjustments to treatment plan may be made depending on results of the biopsy.