A wart is a growth caused by a virus called the human papillomavirus (HPV). The term plantar comes from medical description for the sole of the foot. Any wart on the bottom of the foot can be called a plantar wart, but there are many types of warts which can affect the feet.
Types of Warts
Common warts are flesh colored or brown, thick and dome shaped, forming on the non-weightbearing surfaces of the foot.
Flat warts are typically small, slightly raised lesions, smooth, flat lesions that occur in a line or cluster on the outside of the foot or the ankle.
Periungual warts occur around or under the toenails and are difficult to treat and can be painful.
Mosaic warts appear large, but are general several smaller warts grouped into a cluster or formed a plaque. They tend to bleed with easily and can be dry, cracked or scaly.
Digitate warts are uncommon on the feet, but can be found on the toes. They tend to grow out with multiple fingerlike projections.
The human papillomavirus penetrates the skin through small breaks in the surface. Excessive moisture can cause small breaks in the skin, which can give the virus an opportunity to penetrate into the skin. Swimming pool, hot tub areas and public changing rooms are common places to pick up the virus.
The virus can also be implanted into the foot by a splinter or a piece of glass. The warts are contagious and can spread to other parts of the foot and to other people, especially to those who use the same shower, bath or changing area.
Children, individuals who frequent swimming pool areas and public changing rooms and individuals with a weakened immune system are more vulnerable to contracting the virus and developing plantar warts.
Warts have their own blood and nerve supply. Commonly, pinpoint black areas are visible on the warts surface. These black dots are the wart’s superficial network of capillaries, but may only be visible after the top layer of callus tissue is removed.
misconception about plantar warts
A common misconception about plantar warts is that they have roots which can grow deep into the tissues and attach to the bone. This is not true.
A wart only grows in the top layer of skin and although the wart may extend slightly deeper, as seen in this picture above, this is generally due to the mechanical forces from walking, pushing the wart deeper into the tissue. are flesh colored or brown, thick and dome shaped, forming on the non-weightbearing surfaces of the foot.
Many people will mistake a wart for a corn or callus. This is common as the top layer of the wart is very callused and thick and can appear much like a callus. In the picture to the right, a wart is visible on the bottom of the big toe.
There are multiple pinpoint black areas centrally, surrounded by callus tissue. In many cases, it is difficult to distinguish between a wart and callus until the top layer of the callus tissue is removed. Not all warts will have visible pinpoint black areas, which is why it is important to see a podiatrist for evaluation.
What Plantar warts look and Feel
Warts can look and feel like a callus or a corn and many people with warts complain of feeling like they are walking on a pebble in their shoe. Although many people will never experience much pain with warts, in most cases they are painful.
In some cases, the warts can be very painful. Some feel like they have a piece of glass stuck in their foot, while others feel sharp pain with every step.
The surrounding area can become red and inflamed after extended periods of walking and pressure on the wart. Some warts can become very large and extremely painful, as seen in the image above.
How to Treat Plantar Warts
There are a number of treatments for warts and the treatments range from duct tape to surgery. The type of treatment depends partly on the size, location and number of warts and the patient.
When there are multiple warts over the entire sole of the foot, it is recommended to try topical and oral medication before considering surgery. If there is only one wart, surgery many be a reasonable first step. Warts in between the toes or under the nail may require different treatment regimens than warts on the sole of the foot.
Many people find that home treatments are the most convenient for their schedule. Others are willing to make weekly visits to the doctor’s office for acid treatments, while some people are want to have surgery to remove the warts.
Treatment for Children
In children, warts may go away spontaneously. If the wart is not causing any pain, it is reasonable to initially watch the area as a first line of treatment. Make sure the wart is not increasing in size and make sure it is not spreading.
Warts in children may also go away if you have the child draw a picture of the wart and then bury it the back yard, burn it in the fireplace or throw it away.
The power of suggestion works effectively in children and the body’s natural immune response may kick in. If the wart does not resolve in 4 weeks make an appointment with your pediatrician or podiatrist.
Home Remedies for Plantar Warts
Although not researched like other wart treatments, many people claim wonders with some simple home treatments. The advantage is that they are cheap and most do not have side effects.
1. Apple Cider Vinegar
Take a cotton ball and pull off a piece that resembles the size of the wart. Soak it in vinegar, squeeze out the excess and place on the wart. Cover the wart with tape and sock before sleep. Use daily for 7-10 days.
2. Potato, garlic or banana peel
Each involves rubbing the food product on the wart and then covering the wart with a bandaid, tape or duct tape. The potato wart cure is a folk remedy that developed long ago. It actually involves burying the potato in the back yard after applying it to the foot. No kidding. This has been the folk remedy for years and many people still claim it works. As one would imagine, no study has proven it’s benefit. But, do not underestimate the power of suggestion.
3. Duct Tape
This is the one home remedy that has been researched quite a bit. When evaluating treatments like the above mentioned home remedies, researchers noticed something in common: occlusion. In each treatment, the wart is occluded with a bandaid, sports tape, moleskin or duct tape.
Initially, research showed that as long as the wart was occluded, the therapy seemed somewhat beneficial. Later, some proposed medicinal benefits of the adhesive, which have not been proven. In the popular 2002 study on duct tape, researchers found that duct tape was more effective than cryotherapy (freezing warts).
Once the duct tape remedy made the news, it was over-hyped and the effectiveness was overstated. Recent research since has shown no benefit of duct tape over moleskin. The key with most treatments is occlusion.
How to Use Duct Tape
To use duct tape as a treatment, wash all the oils off of the foot and let the foot dry. Cut a piece of duct tape larger than the wart and place directly over the wart. Keep the tape on until it starts to peel off.
Replace with a new piece of duct tape and repeat for about 7-10 days. In the study, participants soaked their feet in warm water and gently rubbed the wart with an emery board for 2 months or until the wart was gone. DO NOT rub aggressively with a pummice stone.
This may cause shedding of the virus and at the same time cause breaks in the surrounding skin, resulting in further spreading of the warts.
4. Over The Counter
Products at the drug store are typically made with salicylic acid and are moderately effective. Salicylic acid is one of the mainstays for treating warts, but is generally not sold in high enough concentrations in non-prescription products to be effective.
Most medications require daily application and will take weeks to work, if they do work. Although covering the wart and medication with a bandaid or duct tape may increase effectiveness, be careful. The acid can burn the surrounding skin and cause ulceration and resulting infections.
Do Not try these medications if you are diabetic!
treatments your doctor may use
1. Liquid Nitrogen
Also known as freezing or cryotherapy, liquid nitrogen is the most common treatment used by primary care doctors and pediatricians for warts.
A blister usually forms after treatment and although application is typically not painful, there may be some pain afterwards.
2. Salicylic Acid
This is one of the most commonly used medications for the treatment of warts. It is popular because it is well tolerated, not painful and results in little scarring. But, eventhough it can be effective, the destructive process is slow and treatment period is long.
3. Monochloracetic acid/trichloracetic acid
These acids used to be very common topical treatments, but have lost some favor. Many have found that patients tend to have some inflammation and pain with the treatment.
When used effectively, the area may blister, become red and need to be drained by the treating doctor. Although the treatment period may be faster than with other acids, many find the weekly treatments uncomfortable.
A popular treatment for warts as the precription name Canthacur® (also includes podophyllin and salicylic acid) this tends to be effective and well tolerated. Treatments are usually 1-2 per week after reduction of excess callus tissue. This is not approved by the FDA for the treatment of warts.
Also known as Aldara®, this wart medication is approved for treating genital warts but research has shown it to be effective for plantar warts as well.
This is a prescription immunotherapy medication that encourages your body to release immune system to fight off the warts. This is a medication used at home every other day.
6. Oral Medication
Only a couple of oral medications have been used for treatment of warts and their effectiveness is controversial.
A popular treatment for resistant warts, immunotherapy attempts to use your body’s natural immune system to fight off the warts. Immunotherapy is used in patients with a large number of warts, warts covering a large percentage of the surface of the foot and in resistant warts.
It should not be the first line of therapy. Other therapies should be tried initially. The warts are injected with different agents known to stimulate your body’s immune response.
Commonly know for it’s use in reducing stomach acid, research has showed that cimetidine can also be effective in treating warts. The dosage ranges from 20 mg to 30 mg/kg daily in divided doses. Cimetidine seems to work best in patients under the age of 17, but may need to be taken for 2-4 months. Discuss the treatment with your doctor.
9. Vitamin A
Can be used as a topical therapy or taken orally. Dosages vary and long term high dose vitamin A can be toxic.
Removing the wart surgically may seem to be the quickest way to a cure. Warts are typically removed by blunt dissection, but some doctor’s will use a laser. Laser excision is not necessarily more effective.
The recurrence rate tends to be just as high after blunt dissection, laser surgery or topical treatment. Depending on the number of warts and size, the surgery may be painful afterwards and patients are generally limited to minimally walking with a surgical shoe for about 10 days and some discomfort for 2-3 weeks.
For solitary warts, this may be the best treatment option. Scar tissue is a possible complication and as with all surgeries, infection is possible.
Treating warts is difficult and there is no one “gold standard” for treatment. What works for one person may not work for the next. The treatment that resolved multiple warts in 2 weeks for one person may not help a solitary wart after months of treatment in another person. Considering the varying types and locations of warts, treatments will vary from patient to patient.
There is no harm in trying over the counter or home remedies (as long as you are not diabetic) initially before seeking treatment in the doctor’s office. It is recommended to start with conservative therapy initially before considering immunotherapy or surgery. Your doctor may want to biopsy the wart if it appears unusual or is not responsive to treatment.
Some warts may develop into cancer or cancer may simply appear like a wart. This is uncommon, and it is not recommended or necessary to biopsy every wart. No matter which treatment you may have had, there is always a chance for recurrence.