Verruca

A verruca is caused by the human papillomavirus (HPV). There are numerous strains of the virus but verrucas are only caused by HPV types 1, 2, 4, 27 and 57. The viral infection affects the epithelial cells in the skin of the foot, making them over-grow and thicken, causing small rough lumps known as papules.

Verrucas are also known as plantar warts as they develop on the plantar surface of the foot, commonly known as the sole.

HPV isn’t highly contagious, however, a wet environment can make the spread of infection easier. The virus can be spread through contact between bare feet and HPV-contaminated surfaces in changing rooms and shower cubicles. The virus can even survive outside the body for over a year. Verrucas are one of the most common kinds of wart and can affect you at any age. However, warts, including verrucas, are more likely to appear when you’re a teenager or young adult.

You’re also more likely to get a verruca if you are immunosuppressed. This may be because you’re receiving immunosuppressants due to a transplant or another condition, or receiving treatment that can weaken your immune system such as chemotherapy. Having a condition which weakens your immune system such as some blood cancers or AIDS will also increase your risk of verrucas.

Verrucas often go away naturally, especially with children, but this can take time. In children, one in two verrucas will disappear within a year. In adults, it can take several years for a verruca to go away.

Verrucas can be treated with over-the-counter or prescribed verruca removal medications, by freezing (cryotherapy), or, very occasionally, with minor surgery.

A verruca looks like a flat, white growth on the sole of your foot. In the centre of the verruca, there may be one or more tiny black dots under the skin. A verruca can appear on its own or in a cluster with several other verrucas (mosaic warts).

Verrucas are usually found in areas of the foot which withstand a lot of pressure, like the balls of your feet. Because of this pressure, the verruca is often flat.

Verrucas are largely symptomless but can cause sharp pain when you put weight on the affected area of your foot.

There are several other conditions that cause similar symptoms to a verruca, so it's important to go to your GP for a diagnosis. Although some of these are rare, they include:

• Corns
• Calluses
• Black heel
• Verrucous squamous cell carcinoma
• Actinic keratosis
• Lichen nitidus
• Keratoderma
• Lichen planus
• Seborrhoeic keratosis
• Malignant melanoma

Although a verruca can often disappear without treatment, this can take time.

If you’re worried about a verruca, talk to a pharmacist. They’ll advise you on how to get rid of verrucas and recommend over-the-counter medication for verruca removal.

If over-the-counter medication fails to treat your verruca, see your GP. You should also see your GP if you have a verruca that’s:

• Causing you considerable pain or discomfort
• Bleeding
• Spreading or getting bigger

Your GP will examine your verruca and check your feet for other verrucas. Your GP may prescribe a verruca removal treatment or refer you for further treatment, such as cryotherapy. Very occasionally, your GP will refer you to a dermatologist, a consultant specialising in skin conditions.

To reduce your risk of catching a verruca, avoid going barefoot in public places.

If you have a verruca on your foot, to prevent spreading the virus, you should:

• Avoid touching, picking or scratching your verruca
• Wear a verruca sock or waterproof plaster over your verruca when swimming
• Wear flip flops when using communal showers and changing rooms
• Only wear your own shoes and socks

To reduce the chance of spreading the virus to another area of your body, you should:

• Change your socks or tights daily
• Avoid scratching your verruca
• Have a nail file or pumice stone that is specific for the area near your verruca

Treatment is not always necessary, especially if the verruca is not causing you any pain. Many will disappear without any treatment at all, but this can take several years.

Your GP may prescribe verruca removal medication containing salicylic acid to burn away your verruca. You should soak your feet in warm water and file any thickened skin before applying the medication. You’ll need to apply the treatment daily for at least 12 weeks and take care not to apply the acid to the surrounding healthy skin. If the surrounding skin becomes sore, red or itchy, you should stop treatment until it settles. If you have diabetes or poor circulation, you should talk this through with your GP.

Alternatively, your GP may recommend cryotherapy, which uses liquid nitrogen to freeze off warts, including verrucas. Your doctor can apply liquid nitrogen onto the affected area by a spray or using a cotton bud. It should freeze the verruca for between 5 and 30 seconds. For the treatment to be effective, a thick verruca may need to have the outer layer shaved first. You may find that cryotherapy causes blisters, burns or pains, and it’s not usually recommended for children. Cryotherapy should be repeated every month and you may need several treatment sessions.

In some cases, your GP may suggest combining salicylic acid medication with cryotherapy and a number of studies have shown this to be particularly effective. This is where you apply salicylic acid to the verruca in between cryotherapy treatments - unless there’s blistering.

If medication and/or cryotherapy fails to remove your verruca, your GP may suggest minor surgery. This might involve having your verruca lasered off, scraped away (curettage) or treated with light therapy (photodynamic therapy). Your GP may also recommend some special creams that can kill the virus, stop cells from multiplying, or are usually used for skin cancer.

Other possible treatments for verrucas include:

• Verruca needling – stimulating the body’s immune response to the virus by puncturing the verruca to cause bleeding under local anaesthetic
• Swift microwave therapy – a precise dose of microwave energy is targeted at the verruca, heating and destroying it – this only takes a few seconds and anaesthetic is not needed
• Dithranol
• 5-fluorouracil (5-FU)
• Formaldehyde
• Glutaraldehyde
• Podophyllotoxin
• Topical immunotherapy

There is a risk that a complication occurs during your verruca treatment. You may find that you have additional pain, infections, spread of the verruca or scarring as a result of your treatment. You can talk to your doctor about any concerns.

Can you get rid of a verruca quickly?

A verruca can sometimes disappear quickly. In some cases, it may only take one cryotherapy session before your wart falls off.

However, because a treatment method was fast for one person, it doesn’t mean it will be like that for all, so it’s good to be patient.

How do you know when a verruca is dying?

You’ll know your verruca is dying as it starts to change colour. When it's dead, it will have a black appearance as the blood supply has been cut off from the area.

What happens if a verruca is left untreated?

In most cases, an untreated verruca will clear over time and not cause any more problems, however, you may find that they continue to cause you pain.