What is a Plantar Wart
A plantar wart also known as a verruca or verruca pedis is a skin condition that is caused by a virus (the Human Papiloma Virus).
This virus is very common, and more than 100 kinds of the virus exist. But only a few of them cause warts on the feet.
When the virus infects the skin it ‘hijacks’ the normal basement cells and causes them to reproduce abnormally. The body does not realise there is a virus and the wart goes undetected. The common features of a wart are seen bellow.
|NORMAL SKIN||PLANTAR WART|
The green area above represents the cells that are infected with the virus. The viral cells cause an exaggeration of the dermal epidermal junction, reduce the normal striations of the skin and draw in blood vessels resulting in there appearing to be black dots on the surface of the wart.
Causes of Plantar Warts
The virus needs to enter the skin and infect the basement epithelial cells. The skin is usually a strong barrier against viral infections but certain factors reduce the effectiveness of the skin these include:
- Feet being excessively wet and coming into contact with the virus (Pool or public showers)
- Reduced immunity
Diagnosis of a Plantar Wart
Diagnosis is typically based on the signs and symptoms of a wart.
The signs and symptoms are:
- A small, fleshy, rough, grainy growth (lesion) on the bottom of your foot, usually the base of the toes and forefoot or the heel
- Hard, thickened skin (callus) over a well-defined “spot” on the skin, where a wart has grown inward
- Black pinpoints, which are commonly called wart seeds but are actually small, clotted blood vessels
- A lesion that interrupts the normal lines and ridges in the skin of your foot
- Pain or tenderness when walking or standing
- Pain can be reproduced by squeezing the outside margins of the wart
Treatment of a Plantar Wart
There are many treatment options available for warts ranging from surgical excision of the lesion to doing nothing and waiting for them to go away.
At the Foot and Ankle centre we provide an option that is minimally painful, minimally expensive with a high success rate. This is by using a topical ointment called Cantharidin.
- What is Cantharidin:
- Cantharidine is a substance derived from the blister beetle Cantharis Vesicatoria. In the 1950s it was used in the US to treat warts. However in 1962 due to new manufacturing regulations it lost its FDA approval and was removed from the marker.
- This saw a decline in its use until recently, where it has been re-evaluated as a wart removed that does not cause significant pain or scarring
- How does Cantharidin wart.
- Cantharidine causes a blister to form on the wart or growth
- This action lifts the wart off the skin.
- The action of cantharidine does not go beyond the epidermal cells and the basal layer remains intact (therefore no scarring)
- What is involved
- The overlying callous is reduced
- A Cantharidine solution (important to get the percentage right) is accurately applied to the wart or molluscum
- The liquid is allowed to dry and then covered and sealed for 1 day for warts on the dorsal of the foot and 3 days for warts on the plantar surface of the foot
- Within 24-48 hours a blister will form
- Over the next few days the blister will dry and the lesion may fall off
- Healing is normally complete within 4-7 days
- Resistant warts may require a repeat procedure
A podiatrist who has experience in applying Cantharidin should perform the procedure to avoid any adverse side effect. Consult with the foot and ankle centre to see if Cantharidin is the right treatment option for you.