What are plantar warts?

Warts are localised thickenings of the skin, and the term ‘plantar warts’ is used for those that occur on the soles of the feet (the ‘plantar’ surface). They are also known as verrucae or verrucas. Medical professionals will often refer to them as VPs, which is short for the medical term, verrucae pedis.

What causes plantar warts?

Warts are caused by infection in the outer layer of the skin (epidermis) with a virus called the ‘human papilloma virus’. There are many different strains of this virus, and plantar warts are usually due to just a few of these strains. Infection makes the skin over-grow and thicken, leading to a benign (non-cancerous) skin growth (the wart). Plantar warts are caught by contact with infected skin scales – for example from the floors of public locker rooms, shower cubicles and the areas around swimming pools, or even from within your own home. The virus is not highly contagious, and it is unclear why some people develop plantar warts while others do not. The virus enters the skin through tiny breaks in the skin surface. Moistness and maceration of the skin on the feet probably makes infection with the virus easier.

Are plantar warts hereditary?

No.

What are the symptoms of plantar warts?

In most cases plantar warts cause no symptoms and can be painless. Some plantar warts can be uncomfortable, particularly if they are present on a weight-bearing area.

What do plantar warts look like?

Plantar warts can occur anywhere on the soles and toes, and often affect the weightbearing areas. They vary in size from just a few millimetres to more than one centimetre. They may have a rough surface and protrude from the skin. An individual may have one or many verrucae and can also have warts elsewhere on the body. The term ‘mosaic wart’ is used for tightly packed clusters of small plantar warts that resemble a mosaic.

How will plantar warts be diagnosed?

The diagnosis is usually based on the clinical appearance. Sometimes it can be difficult to tell a plantar wart from a corn. Your podiatrist may need to pare down the area to investigate, and sometimes this will make the wart bleed, this is considered normal.

Can plantar warts be cured?

The HPV virus is very resilient and can resist desiccation, freezing, and prolonged storage outside of host cells. There is no guaranteed cure, but some treatments can help to clear warts. The best chance of cure is in young people who have not had their warts for very long. If you are older, have had the warts for a long time, have an illness that affects your immunity or are taking immunosuppressant medication, treatment can be less successful or unsuccessful. Most verrucae will clear with time and can be left untreated if not causing problems. When deciding whether to treat plantar warts or not, the following pros and cons should be taken into account:

• Warts usually resolve by themselves without leaving a blemish or scar.

• Successful treatment of a viral wart does not prevent further warts.

• Some warts can be very stubborn. Treatment does not always work and may be time consuming.

• Treating plantar warts may be painful, depending on which treatment type is used.

• Some old fashioned treatments eg acids, can damage the surrounding healthy tissue.

• Podiatrists can use treatments that you won’t be able to buy in shops or pharmacies.

How can plantar warts be treated?

Previously, most people treated their own warts with over-the-counter preparations from pharmacies. However, there is a danger that you could be treating something that is not a wart and causing damage to the skin. You should see a podiatrist to have a definitive diagnosis. Podiatrists have access to products that cannot be purchased in shops or pharmacies. You should not be tempted to self-treat if:

• The lesion is bleeding, painful or changes in appearance or interferes with your daily activities

• You have treated the wart but it persists and starts spreading

• You have diabetes or poor sensation on your feet

• You have weakened immune system because of immune-suppressing medications, AIDS or immune-deficiency disorder.

Because there are so many strains of the virus that causes verrucae, no one treatment option will work for every person, or on every wart. If one treatment option does not work after the treatment-specified time then you should try another option. It is best practice to leave a break between different treatment types and sometimes even between cycles with the same treatment. Your podiatrist can advise on this.

Treatment options:

Here at Salisbury Courtyard Clinic we offer Plasma Sublimation (vaporisation) for adults and older children; Verrutop (dessication) for younger children aged 6+; occlusive taping for children under 6 and nervous children of any age.

More about treatment options:

• No treatment: Up to 65% of viral warts including plantar warts resolve by themselves without any treatment within two years of appearing. Many warts may take up to ten years to resolve. Plantar warts that are not causing any adverse symptoms such as pain can be left alone to self resolve.

• Plasma Sublimation: This method uses plasma to sublimate or vaporise the wart without causing destruction to the surrounding tissue. Clinic treatments are monthly, no dressings or self care is needed by the patient between clinic treatments. Read more about this treatment here.

• Topical desiccation: This method dries out the wart using a Nitric-Zinc complex solution. Clinic treatments are every two weeks for a cycle of 6 treatments. Dressings may be needed depending on the location of the VP.

• Occlusive Tape: Sometimes called the ‘tape method’. Although there is conflicting evidence regarding the effectiveness of tape in the treatment of cutaneous warts, it might still be well worth trying, especially in children. This is a cycle of filing, soaking and covering the wart. Your podiatrist can show you the protocol that has the best results.

• Cryotherapy: freezes any skin cells containing the wart virus. This is done every two weeks for 3 sessions, this is called a treatment cycle. The area where the wart is located may require padding. Cryotherapy can be painful and may cause blisters and burns, and because of this is not usually recommended for children. Several cycles of treatment may be needed, with gaps between cycles.

• Salicylic acid paints and gels: These are available in different strengths. Salicylic acid works by removing the outer dead layers of skin and triggering the immune system into clearing the virus. Over the counter products are weaker than those used by a podiatrist. Frequently, home treatment results in damage to healthy skin and may not affect the wart at all. Stronger preparations are used by podiatrists, patients must follow strict instructions and attend weekly appointments to avoid unnecessary damage to healthy tissue.

• Occlusive Tape: Sometimes called the ‘tape method’. Although there is conflicting evidence regarding the effectiveness of tape in the treatment of cutaneous warts, it might still be well worth trying, especially in children. This is a cycle of filing, soaking and covering the wart. Your podiatrist can show you the protocol that has the best results.

• Caustics: other approved topical treatments for plantar warts include formaldehyde gel, gultaraldehyde and silver nitrate caustic pencils.

• Surgical removal of warts is an option if topical treatments do not work. Options include tissue destructive laser therapy or curettage and cautery after a local anaesthetic injection into the skin. These procedures are painful and can lead to uncomfortable scarring. The wart may come back in the scar after surgery.

• Faulkners needling: a local anaesthetic is needed and the wart is pulverised hundreds of times using a fine needle to stimulate the body’s immune system.

• Microwave therapy: known as Swift emblation, a microwave pulse is sent through the verruca to cause destruction.

• Other topical preparations: many other topical preparations exist to treat warts but are not used so much nowadays due to the high risk of skin damage and low cure rates.

• Other treatments exist, such as contact immunotherapy, photodynamic therapy, laser therapy, hypnotherapy, homeopathy, acupuncture, and herbal treatments. There is currently no proven results from research showing these treatments are efficacious.

What can I do?

• Wear comfortable shoes and do not share your shoes or socks with anyone else.

• Special pads to relieve pressure on plantar warts can be bought at a chemist or from your podiatrist.

• Keep your feet clean and dry. Change your shoes and socks daily.

• Do not go barefoot in public places.Plantar warts should be covered with waterproof plasters or rubber ‘verruca socks’ if you go swimming.

• When treating the wart, dispose of any skin filings hygienically and do not use the emery board or hard skin removal tools elsewhere as this could spread the infection.

• To avoid spreading viral warts to other parts of the skin (autoinoculation) do not pick or scratch plantar warts.

• Do not use same pumice stone, nail file and or nail clippers for your warts and your healthy skin and nails.

• To get the maximum chance of a cure, chose treatment under the care of a podiatrist rather than a home treatment.

More information: This leaflet has been compiled from a variety of sources including: British Association of Dermatologists ; College of Podiatry: https://onlinelibrary.wiley.com/doi/pdf/10.1002/psb.884; www.emedicine.com/emerg/topic641.htm; www.emedicinehealth.com/articles/20312-1.asp; www.dermnetnz.org/viral/viral-warts.html