Verrucas - What are verrucas?

Verrucas, verrucae or plantar warts are small lesions, rough lumps, warts or growths that are found commonly over certain areas of the feet like the heel and the balls of the feet that commonly bear pressure.

Verrucas usually resolve on their own but may need treatment if they cause symptoms. For example, around half of these will disappear within one year, two thirds go away after two years and the rest one third are persistent and resistant to therapy. 1-5

Causes of verrucae

Verrucas are caused by a viral infection by Human papilloma virus (HPV) types 1 and 2 and sometimes 4. This virus attacks the topmost layer of the skin or the epithelium. This causes the cells to proliferate or form a growth or a raised plaque. Sometimes it may take up to a year or two after the initial viral invasion for the lesion to show up. Verrucas are not cancerous.

Mode of spread

Verrucas are usually spread by person-to-person contact. Common modes of spread are sharing communal showers where other people with verrucas have also bathed. Infections are common if the skin of the feet are damaged or cut or ulcerated in any manner.

In addition spread may also occur if there is scratching, nail biting, shaving or finger sucking. This results in spread to different areas of the body of the same person.

How common are verrucas?

It is found that most people get these verrucas at some point in their lives. Women are slightly more affected than men. These are more common among children and teenagers affecting around 4-5% of the population but are uncommon in infants.

Some professions are more at risk of these warts that commonly affect the hands. These include butchers, abattoir workers, engineers and office workers.

Symptoms and signs of verrucae

Most people with verrucae complain of pain while walking. Pain due to verrucae of the pressure areas of the feet may lead to an altered posture during walking and this may lead to leg or back pain as well.

Families are affected but this disease is not inherited. It is highly contagious and more than one member of the family is affected at once.

Those with eczema, low immunity, diabetes, AIDS, who have received a transplanted organ and are on immunosuppressant medications and patients of leukemias and lymphomas are at a higher risk of this infection. Around 50% of people who have had a kidney transplant develop warts within five years.

The warts appear firm and may have pinpoints of spots over it. They are located on pressure areas such as heels or balls of the feet. The pressure makes them appear flattened. More than one wart may be fused to form a mosaic wart.

Diagnosis of verrucas

Diagnosis is made by clinical examination and also other conditions that mimic these warts need to be ruled out. These include:

  • corns
  • calluses
  • black heel
  • verrucous squamous cell carcinoma (skin cancer of the feet)
  • arsenic induced keratosis
  • actinic keratosis
  • cutaneous horn
  • lichen planus
  • lichen nitidus
  • molluscus contagiosum
  • seborrhoeic keratosis etc.

Treatment of verrucas

Usually there may be no treatment if not painful or symptomatic. In many patients steps for prevention of recurrence and spread are advised. Those who have a depressed immunity; painful warts; have persistent warts for over 2 years; or desire treatment, are candidates for treatment.

Treatment is with salicylate medications. These are available as gels, paints, plasters, colloidion etc. Other preparations contain formaldehyde and glutraldehyde. Some prefer cryotherapy or freezing the warts till they fall off. Rarely surgery and removal of the warts are undertaken. Injections of the verruca with interferon, 5-flurouracil, bleomycin etc. are other options.


Common complications include pain, secondary bacterial infections, scar formation etc. There may psychological impact of the verrucae especially in children. In patients with a depressed immunity there is a rare possibility of the verrucae turning into cancer.

Outcome of verrucas

In many patients there may be treatment failure and there is a high risk of recurrence. In addition, most disappear within two years without treatment and at least 90% of warts present at age 11 years, will be gone by age 16 years.

Prevention of verrucas

Patients are advised to wear waterproof verrucae socks to prevent spread. The verrucae should be covered with a waterproof plaster when swimming. Shoes and flip flops should be worn at community showers. Shows, socks or towels should not be shared. Scratching and itching should be discouraged to prevent spread to other parts of the body.

Causes of verrucas

Verrucas (verrucae) or plantar warts are small, rough, raised or flattened lumps that occur over the pressure areas of the feet. These are commonly caused by infections with different strains of the human papilloma virus (HPV).

The virus may be isolated from the skin cells of verrucae. Around half of these disappear on their own in a year. Two thirds of the verrucae persist for at least two years and disappear without therapy. The other one third persists for more than 2 years and is resistant to therapy.

Who gets verrucas?

Most people will get verrucae at some point in their lives and women get it slightly more commonly than men. The peak incidence is seen in children with 4 to 5% affected but infants are usually spared. 1-5

Causative organism of verrucas

There are over 100 different types or strains of HPV that have been identified. Different strains of HPV are responsible for causing different types of warts. For example, types 1 and 2 are commonly implicated for causes plantar warts or verrucae. Type 4 is also found in some cases.

The virus invades the top most layer of the skin called the epithelium and starts replicating within these epithelial cells. This may lead to multiplication of the cells and formation of plaques or papules or the flattened warts. The incubation period is often up to a year. This means from the time of invasion of the virus to formation of the warts, the time taken may be up to a year. HPV is highly contagious.

Method of spread of verrucas

HPV from the verrucae may spread through close skin-to-skin contact. These warts are contagious as long as they are present on the body as they contain the live virus within them. Sometimes the virus may also spread by sharing objects like towels, socks, shoes, baths and community showers with infected persons.

In addition, those who have wet, soft, ulcerated or sore skin of the feet are more likely to get the infection than those with dry and intact skin of the feet.

The virus particularly spreads to more than one part of the same individual’s body if they scratch, itchy, bite (nails with finger warts), suck (fingers with warts) or shave (face or the legs with warts) over the warts. This is called auto-inoculation. This trauma usually leads the warts to break up and bleed and helps spread the virus to other parts of the body or to other individuals.

Despite spread due to sharing community showers or baths and pools, the National Curriculum suggests that all children should learn to swim as it helps to prevent death from drowning and risk of verrucae should not deter children from acquiring this skill.

Risk factors

Some individuals are more at risk of getting verrucae. These include certain professions like butchers, engineers, office workers etc. Those who have low immunity like in people with AIDS or those taking immunity suppressing medications after a transplant are at a risk of verrucae. In fact many people get warts (plantar or other types) after a kidney transplant. Diabetics are at a risk of these warts and have difficulty in preventing a recurrence after cure.

Symptoms and diagnosis of verrucas

Verrucas (verrucae) or plantar warts affect the pressure areas of the feet. These affect most individuals at some points in their lifetime. Most commonly affected are those between ages 12 and 16.

In most individuals the warts go away without therapy within 2 years. One thirds of cases are more resistant to therapy and may have persistent lesions beyond two years. 1-5

Verruca symptoms

Symptoms of plantar warts or verrucae include:

  • Warts may appear in various shapes and sizes. For example, the size of a wart can range from 1mm to over 1cm in diameter.

  • Verrucas are often painful due to their location. As they commonly occur on pressure areas of the feet like the heels or the balls of the feet, they may hurt. Most patients tend to avoid putting weight over the warts and end up with an altered posture and gait. This leads to pain in the legs and the back as well.

  • Sometimes these are itchy.

  • On scratching the warts may bleed as well.

  • Verrucae may be single or more than one clustered together. These are called mosaic warts.

  • The verrucae are round or oval in shape and are firm and raised or flattened. Their surface is irregular and typically like a cauliflower.

  • The skin around the verrucae is white in color. There is often a black dot in the centre that is actually the blood vessel lying underneath.

  • Verrucae may not be typically raised but may be flattened due to their occurrence over the pressure areas of the feet and constant pressure over them. The weight of the body may force the warts to grow back into the skin. This leads to pain as well.

  • Verrucae may spread due to scratching, biting, finger sucking or shaving to other parts of the body like fingers, nails, mouth, face etc. This occurs due to breakage of the warts and release and spread of the virus to other areas.

Diagnosis of verrucas

Diagnosis of plantar warts or verrucae is commonly made by clinically examining them.

The physician takes into account several factors like history of sharing community showers etc., familial or partner history of such warts as these are contagious and history of eczema and conditions where there is a risk of reduce immunity like AIDS, transplant, leukemias or lymphomas.

The wart is examined for number, location, size, shape, colour and texture of the wart’s surface

Following examination the physician or podiatrist treating the wart may gently cut away the surface of the wart to reveal a small black dot in the centre. This confirms a verrucae.

Blood tests may be advised to check for causes of low immunity and diabetes that result in resistant cases.

Ruling out other conditions

Other conditions that need to be ruled out before diagnosis of verrucae are confirmed include:

  • corns and calluses that are areas of thick dry skin which are caused by excessive pressure or friction

  • black heel

  • verrucous squamous cell carcinoma (skin cancer of the feet)

  • arsenic induced keratosis

  • actinic keratosis

  • cutaneous horn

  • lichen planus

  • lichen nitidus

  • molluscus contagiosum

  • seborrhoeic keratosis etc.

A Molluscum contagiosum (MC) for example is a contagious skin infection that is caused by the Molluscum contagiosum virus. There are small, firm, raised spots on the skin in this condition.

Squamous cell carcinoma is skin cancer that appears as crusted lumps that are slow growing and often painful. Rarely existing warts may grow into cancer.

Treatment of verrucas

Verrucas or plantar warts normally go away on their own in a year or two in most people. In around half individuals the warts resolve in a year. In two thirds the warts resolve within two years. In the remaining one third however the warts may persist and may be resistant to treatment. 1-5

Treatment for verruca is recommended in only some special cases. For the rest prevention of recurrence and spread are the only measures that are adopted.

Who requires treatment?

Treatment is recommended in:

  • Those with suppressed immunity like after a kidney or liver transplant and those with diseases like AIDS that causes suppression of immune functions.

  • Those in which the warts have become painful and have led to difficulty in walking and bearing weight necessitating treatment

  • Patients who desire therapy

Treatment of plantar warts or verrucae

Verrucae are curable but no single treatment can be guaranteed to be effective in every case. In addition not all verrucae need to be treated.

The highest cure rates are in young people with recent onset of symptoms or warts.

Self-care for verrucas

Self-care and treatment may be begun at home. The wart is first pared down, or filed with sandpaper and then the foot is soaked in warm water for at least 5 minutes. This softens the wart and helps treatment. This is to be repeated every night for at least 12 weeks and the surrounding normal skin should also be treated. Treatment is stopped for a day or two if the skin becomes tender.

Treatment for mosaic warts

Those with mosaic warts may also begin treatment with a salicylic acid of formaldehyde containing gel. If there are a large number of small verrucae the area is soaked for 10 minutes at night in a weak formaldehyde solution.

Salicylic acid preparations

Medications like salicylic acid preparations can be used to treat verrucas. These are available as gels, paints, plasters, colloidion etc. These may be combined with podophyllum resin.

Other preparations contain formaldehyde, glutraldehyde, tretinoin (Retinoic acid) or bezoyl peroxide.

Cryotherapy of freezing therapy

This is done by freezing the affected area with liquid nitrogen, using either a cotton wool swab or a spray. The podiatrist usually pares or sandpapers off the art before this therapy and freezes it with this technique. This therapy may be combined with a salicylic acid preparation.

The treatment is performed once at least three weekly for better cure rates. This therapy is usually painful and may lead to formation of blisters and is thus not used in children.

If there is no change or improvement after 7 or 8 visits of freezing, the treatment is considered to be a failure and is discontinued.

Removal of resistant verrucas

Resistant plantar warts may be removed under a local anaesthetic. The technique involves scraping the verrucae with a sharpened spoon-like instrument called a curette. The remaining raw area is cauterized with electrically heated points. This is also a painful procedure.

Stopping recurrence of veruccas

Sometimes after removal or scraping some medications might be used to stop recurrence or growth. These include interferons, 5- flurouracil, bleomycin etc.

Laser treatment for verrucas

Laser treatment may be used in multiple or mosaic warts in some patients who have failed to respond to other forms of therapy. This therapy may lead to pain and formation of scars.