Plantar Wart

Plantar warts (also known as “verruca myrmecia” or “verruca plantaris”) are common viral skin infections that grow on the bottom of the feet.  They are small, flat, hard circular growths, that look like a corn, callus or blister.   Walking puts pressure on the wart, which makes it grow inward and builds a hard layer of skin overtop.  Walking or standing on the warts may also hurt.

Anyone can get plantar warts: they are not a serious health condition and sometimes go away on their own.  However, they are contagious.  If they persist, they can grow, spread and cause foot pain when you stand or walk on them. 

Fortunately, plantar wart removal can be easily done by a foot specialist or doctor.

Plantar warts form on the bottom of your foot or toe – usually on the weight-bearing parts.  Not all plantar warts are alike:  You can have a single wart (solitary) or clusters (mosaic).  

Visual signs are:

• A small, flat, circular skin-coloured growth or lesion.
• A hard, thickened, well-defined spot on the skin that looks like callus, corn or blister.  
• Black dots (“wart seeds”) on the surface or sole of your foot. 
• The wart may have a crust-like hard layer of skin over it (like a callus).

Other symptoms are:

• Tenderness, pain or discomfort when walking, standing or putting weight on the affected foot.
• Tenderness or pain when touching or putting pressure on the affected area.
• Feeling like there’s something in your shoe that won’t go away.

Plantar warts are caused by the Human Papilloma Virus (HPV) that infects the outer layer of the skin. The virus can enter the skin when bare feet come in direct contact with an infected surface, possibly through tiny breaks in the skin. If the body does not fight off the virus, plantar warts form.  The virus loves warm, moist environments (i.e.: communal showers, locker rooms and around public swimming pools). We recommend wearing flip-flops or shoes in these places. 

Plantar warts occur more frequently in kids and teenagers because of their activities (like playing barefoot with friends in a waterpark on a hot sunny day).  However healthy adults can get them too.  People with weakened immune systems are also more likely to get plantar warts.  

Don’t worry, a plantar wart has no relation to herpes or genital warts. The HPV strain that causes plantar warts is different from the strain that infects the reproductive tract.

Plantar warts sometimes go away on their own, but if they don’t, there is no need to worry:  Plantar warts can easily be removed by a chiropodist, doctor or foot specialist.  

People respond differently to different wart removal treatments, so it is important to find which one works best for you. In general, the more aggressive or invasive the treatment, the higher the success rate. Less invasive procedures will require multiple visits.

The following are some treatment options your chiropodist may discuss with you (from least to most aggressive):

Salicylic Acid

Salicylic Acid is a topical medication that is applied to the wart.  It softens the skin and helps shed layers of skin and wart bit by bit.  It is found in many over-the-counter wart removal products.  The higher the dose of salicylic acid, the higher its effectiveness.

For quicker, more effective wart removal, a chiropodist can prescribe a high-strength salicylic acid topical solution that you can apply regularly at home.  You would then come in for follow-up visits to see how treatment is progressing. Salicylic Acid is a relatively painless option for wart removal.

Cryotherapy

Cryotherapy is a standard, quick, highly effective and non-invasive method for removing plantar warts.  The procedure can be performed in-office by a chiropodist, doctor, or any foot specialist.  A freezing substance (usually liquid nitrogen) is applied to the wart with a cotton swab or spray, effectively freezing and killing the wart and all affected tissue.  A blister is formed around the wart; when the blister dries up over the next few days, the wart may fall off.  

The treatment is repeated by a chiropodist or doctor every 1 to 3 weeks until the wart is fully removed (usually after 1 to 4 treatments, although larger warts may take more treatments).  Cryotherapy also stimulates the immune system to fight off the virus.  The treatment itself takes less than a minute.  It may cause some pain, but the pain is temporary and usually lessens with each treatment. A local anesthetic can be applied beforehand to numb any pain, but it is usually not needed.

Canthacur/Canthacur PS

Canthacur is a potent topical solution applied directly to the wart by a chiropodist.  When the liquid dries, the wart is covered and sealed with a special tape. It is recommended to keep the area dry and covered for up to 24 hours after treatment.  The Canthacur solution lifts the wart off the skin and a blister forms within 24 to 48 hours.  The blister then dries over the next few days and the wart falls off.  Healing is usually complete within 4 to 7 days.  The treatment can be repeated if the wart isn’t fully removed.

Although the treatment itself isn’t painful, the resulting blister may be uncomfortable.

Needling

Needling is a simple, but more invasive wart removal procedure.  A local anesthetic is first applied to numb the area.  The wart is then punctured with a sterile needle approximately 100 times.  This pushes the virus further into the body, which triggers an immune response to help your body fight off the virus that causes plantar warts.  If the procedure is successful, your body’s immune response will fight off any other warts and make them go away.  

Needling is often used for people with multiple warts or clusters (mosaic plantar warts), or for particularly stubborn cases of plantar warts that resist other less invasive treatments.  It is about 70% effective.

Excision

Excision is used for plantar warts that resist other treatments.  The foot is first numbed with a local anesthetic.  Then, as the name implies, the wart is cut away (or “excised”) from the skin.  The base is also cauterized to ensure no living viral tissue is left behind.  There is a risk of scarring, so this method isn’t used unless other treatments have failed.

To schedule a treatment for your plantar warts with our licensed chiropodists (foot specialists), use the booking form below or call 416-769-FEET(3338).

Our Toronto foot clinic is open Mondays to Fridays from 9am-6pm, and Saturdays from 9am-4pm. You do not need a referral to become a patient at our foot clinic.

Plantar warts, although not as contagious as fungal infections (like athlete’s foot or fungal toenails), can be spread through direct contact with an infected surface.  The following precautions will reduce your chance of exposure:  

• Wear flip-flops or a foot covering in communal showers, locker rooms, around swimming pools or any other warm, moist environment – especially if it is publicly shared.  
• Do not touch warts (including your own) and if you do, wash your hands carefully afterwards before touching anything else.
• Keep your feet clean and dry (the virus that causes plantar warts thrives in warm, moist environments).
• Change your shoes and socks daily.
• Do not pick or scratch warts: this will not remove the wart, and can make it worse or spread it to other areas.

To prevent plantar warts, it is also best to avoid sharing the following items:

• Shoes and socks
• Pumice stones
• Emery boards 
• Nail clippers 
• Any other object that touches the skin on your feet.

Similarly, don’t use the same object you use on areas affected by warts on unaffected areas (i.e.: don’t use the same pumice stone that you used on your wart-affected foot elsewhere).