What Are Warts? What Causes Warts?

Warts are skin growths which are caused by the human papillomavirus (HPV) - they are non-cancerous. The virus causes keratin, a hard protein in the epidermis (the top layer of the skin) to grow too fast. Warts are different from moles. While moles are dark and can be quite large, warts tend to be small, skin-colored rough lumps. Warts most commonly appear on a person's hands and feet.

The appearance of a wart can vary depending on what part of the body it is, as well as how thick the skin is. A wart that is located on the sole of the foot is known as a verruca.

What are the different types of warts?

Experts say there are several different kinds of warts. According to the National Health Service (NHS), UK, a survey of 1,000 children with warts found that:

• 74 per cent of them had common warts
• 24 per cent of them had verrucas
• 3.5 per cent of them had plane warts
• 2 per cent of them had filiform warts


• Common warts (verruca vulgaris) - these have a rough surface. They are firm and raised and may have a cauliflower surface type look. They are thickened bumps called papules or plaques. Common warts may appear in any part of the body, but are more common on the knuckles, fingers, elbows and knees. Often they have tiny dark spots which are from blood vessels that have clotted. 

• Verrucas (plantar warts) - these appear on the soles of the feet, sometimes the heel and toes. They usually grow back into the skin because the weight of the person pushes onto the sole of the foot. They can be painful. It is common for verrucas to have a black dot in the middle, with a surrounding hard, white area. The dark dot is the wart's blood supply.


• Plane warts (verruca plana) - plane (plana) means flat. Plane warts are round, flat and smooth. They are generally yellowish, brownish or skin color. They are also known as flat warts and are more common among young children. They are usually found on the hands, legs and face. Adults can have plane warts, but this is unusual.


• Filiform warts (verruca filiformis) - these are long and can usually be found on the eyelids, neck and armpits.


• Mosaic warts - these grow in clusters. Palmar warts are mosaic warts that grow on the palm of the hands and feet.

When should you see your doctor?

If you are sure it is a wart tell your doctor next time you see him/her. Most warts do not need to be treated medically. Most warts disappear on their own. If you are not sure and wonder whether it may be something else, go and see your doctor to have it checked.

You should definitely see a doctor if the wart causes pain, bleeds easily, changes appearance, spreads easily to other parts of your body, or comes back. If you want the wart removed for cosmetic reasons see your doctor. Podiatrists (foot specialists) can give people advice about verrucas.

What are the causes of warts?

Different HPV (human papilloma virus) strains cause warts. The wart-causing virus can be passed on by close skin-to-skin contact, as well as through contact with towels or shoes.

The wart-causing virus can be spread to other parts of the body in the following ways:

• If somebody scratches or bites a wart
• Sucking fingers
• Biting fingernails can cause warts to spread on the fingertips and around nails
• Shaving (face or legs)

A person whose skin is damaged, wet, or comes into contact with rough surfaces is more likely to catch the infection. For example, a person with scratches or cuts on the soles of his/her feet is more likely to catch verrucas in and around public swimming pools.

As we all have different immune systems some of us may develop warts when we come into contact with HPV, while others don't. The risk of catching warts from another person is fairly small, but it exists. Genital warts are much more contagious.

How are warts and verrucas diagnosed?

Warts and verrucas are generally easy for doctors to identify just by looking at them. The doctor may ask whether any other family members have warts. Occasionally, he/she may take some tissue from a wart and examine it under a microscope.

What is the treatment for warts?

The majority of warts clear up without any treatment. How long it takes for them to clear up varies considerably from person to person. They tend to clear up faster among young children. Some warts may take several years to clear up. Less commonly, warts may clear up without treatment within weeks.

Some treatments may cause the skin around the wart to become irritated, others may cause pain, and even blistering. The type of treatment depends on where the wart is located and how many of them there are:

• Salicylic acid - most creams, gels, paints and medicated plasters that you can get at a pharmacy without a prescription contain salicylic acid. Studies indicate that salicylic acid treatment usually gets rid of most warts within three months. It is important to protect the skin before applying treatment. This is because salicylic acid may destroy healthy skin. Petroleum jelly or a corn plaster may be used to protect the skin around the wart.
  
  Before applying the medication soak the wart in water for about five minutes. Rub dead tissue off the surface of the wart each week using a pumice stone or emery board. Make sure you do not share it with anybody else. In most cases treatment is applied daily for about three months. If the skin becomes sore, stop the treatment.
  
  Medications containing salicylic acid should not be used on the face. Patients with poor circulation should not use medications that have salicylic acid without checking with their doctor.


• Duct tape - some people use duct tape in order to get rid of warts. They should never be used for warts on the face. Duct tape is placed over the wart and left there for about six days, and then removed. The wart is then soaked in warm water for about five minutes after which the dead tissue is gently rubbed off using an emery board or pumice stone. It is important that the emery board or pumice stone is not used by anybody else. The wart is then left uncovered overnight and a new piece of duct tape is placed the next day.


• Cryotherapy - very cold liquid, possibly nitrogen, is sprayed on to the wart, freezing it and destroying the cells. A blister develops, which eventually turns into a scab and falls off a week or so later. This treatment has to be done by a healthcare professional and may require a local anesthetic. If the wart is large several treatments may be required over a number of weeks. Cryotherapy has a lower risk of skin irritation compared to medications containing salicylic acid or the use of duct tape. Pharmacies sell dimethyl-ether/propane spray which the patient can use himself/herself - this should not be used on the face.


• Surgery - this is less common for warts. Warts treated with surgery often come back. Surgery has a higher risk of scarring. However, sometimes a doctor may recommend surgery, which will generally be performed under local or general anesthetic. Surgery may be recommended if other treatments have not worked. If the wart is very big it will be cut out. Smaller warts may be scraped off using a curette.


• Laser treatment - a precise laser beam is used to destroy the wart. Laser treatment is usually recommended for warts that are hard to treat.


• Electrocautery - an electric current is used to burn off the wart.


• Photodynamic therapy - the wart cells absorb a chemical. This chemical is activated by light - usually laser light - and destroys the wart cells.


• Chemical treatments - these are available on prescription. They may include formaldehyde, glutaraldehyde and podophyllin. They must be applied only on the wart, and not on the surrounding skin.


• Cantharidin - this is a substance which is extracted from the blister beetle. The doctor will apply it onto the warts. Usually this extract is mixed with other chemicals, applied onto the skin and covered with a bandage. It is painless; however the resulting blister may be uncomfortable. The blister lifts the wart off the skin so that the doctor can them remove the dead part of the wart.

Doctors may sometimes treat pregnant patients, or they may decide to wait until after the pregnancy is over.

If warts have not responded to standard treatments a GP (general practitioner, primary care physician) may refer the patient to a dermatologist (skin specialist). The dermatologist may use some of the treatments below:

• Immunotherapy - the aim here is to get the patient's immune system to destroy the warts.


• Bleomycin (Blenoxane) - this is injected into the wart and kills the virus. Bleomycin is also used for treating some types of cancer.


• Retinoids - these disrupt the wart's skin cell growth. Retinoids are derived from vitamin A.

Antibiotics are not effective for treating warts. Antibiotics are used for bacterial infection, not viral infections. Warts are caused by a virus.

• A common flower that helps wipe out garden insects has also shown promise in eradicating stubborn warts, a study found.

Common warts may be difficult to eliminate completely or permanently, especially those located around and under the fingernails and toenails. Many people who are susceptible to warts will regularly have them, even after successful treatment. Experts say that sometimes more than one treatment approach is needed for better management of warts.

Complications

• Some people who have many warts, especially on their face, may find their self-confidence is affected.


• Some treatments may cause pain and irritate the skin around the wart.


• Although scarring is possible, it is unusual.


• It is harder to successfully treat warts if the patient has a weakened immune system.


• People with weakened immune systems are at a higher risk of their warts becoming malignant. Even so, this is rare.

Prevention

• Do not touch other people's warts.


• Do not use towels, flannels or other personal items of people who have warts.


• Do not share shoes and socks with a person who has verrucas.


• Do not scratch your warts or verrucas. If you do they will most likely spread.


• Wear sandals when going into and out of communal showers.


• Wear sandals when walking around communal pools.


• Cover your wart/verruca with a waterproof plaster (band aid) when you go swimming.


• There are special socks you can buy to cover verrucas.


• Wear gloves in the gym if you have warts on your hands.


• Do not brush, comb, shave, clip areas that have warts.


• When filing or cutting your nails do not use the same utensil on the infected nail and then on the healthy nails.


• Do not bite your fingernails if you have warts near them.


• Keep your hands as dry as possible.


• Wash your hands thoroughly after touching a wart.