Warts

Warts are benign growths of the skin or mucous membranes caused by the human papillomavirus, or HPV. They are usually not dangerous, but they can be contagious, spread to other areas of the body, cause pain, discomfort or cosmetic concern. Sometimes a lesion that looks like a wart may actually be another skin disease or another skin lesion, so unclear cases should be assessed by a dermatologist.

Warts can appear in both children and adults. They are most commonly found on the hands, fingers, feet, around the nails, on the face or on other parts of the body. Plantar warts can be especially troublesome because body weight presses on them while walking and they may become painful.

Some warts can disappear on their own over time, as the body gradually recognises and controls the virus. However, waiting is not always the best option. A dermatologist’s consultation is needed if a wart hurts, bleeds, grows rapidly, spreads, changes in appearance, is located on the face, near a nail, on the sole of the foot, in the genital area, or if there is uncertainty that the lesion is truly a wart.

What are warts?

Warts are growths in the upper layer of the skin caused by the human papillomavirus. The virus affects the growth of skin cells, so a thickening, rough bump or denser patch of skin develops in a particular area.

In everyday language, people often use the word “wart” for many different skin growths, but medically not every raised, rough or skin-coloured lesion is a wart. A corn, blister, papilloma, seborrhoeic keratosis, mole, skin thickening or another lesion may look similar to a wart. Therefore, when a lesion looks atypical, changes, bleeds or does not go away, it is safer to have it examined by a dermatologist.

Common skin warts are usually benign. They are not the same as skin cancer and, in most cases, are not life-threatening. However, they may cause discomfort, recur, spread and create psychological or cosmetic concerns. It is also important not to miss situations where a “wart-like” lesion is not actually a wart.

Why do warts develop?

Warts develop when the human papillomavirus enters the upper layer of the skin. This often happens through very small skin micro-injuries — cracks, abrasions, cuts, irritation or maceration, when the skin has been moist for a long time and has become more vulnerable.

Wart development may be promoted by:

• minor skin injuries;
• nail biting and trauma to the skin around the nails;
• scratching or picking at warts;
• walking barefoot in shared showers, swimming pools and changing rooms;
• sharing towels, shoes or nail-care instruments;
• moist skin and increased sweating of the feet;
• close skin contact during sports or in children’s groups;
• shaving over warts;
• disruption of the skin barrier;
• a weakened immune response or immunosuppressive therapy.

This does not mean that every person who comes into contact with the virus will develop a wart. The body’s immune response, the condition of the skin and the type of virus determine whether the infection appears as a visible growth.

Are warts contagious?

Yes, warts can be contagious. The virus can spread through direct contact with a wart, through infected skin scales or via surfaces such as shared showers, swimming pools, changing rooms and gyms. Warts can also spread from one area of the body to another if a person scratches, picks, shaves over or traumatises them.

Contagiousness does not mean that a wart will necessarily “spread” to everyone who touches it. The virus usually enters more easily through damaged, moist or irritated skin. This is why plantar warts are more often associated with shared showers, swimming pools and changing rooms, where the skin may be moist and surfaces are shared.

To reduce the risk of spread, warts should not be scratched, picked or cut. Use your own towel, your own footwear and individual nail-care instruments. In swimming pools, gyms and shared showers, it is advisable to wear flip-flops or shower shoes.

How can a person get warts?

The human papillomavirus enters the skin through tiny cracks, abrasions or other skin damage. Often a person does not even notice these micro-injuries because they can be very small.

Typical routes of infection and spread include:

• direct contact with a wart;
• floors in shared showers, swimming pools or changing rooms;
• shared towels, shoes or socks;
• shared nail-care instruments;
• scratching, picking or traumatising a wart;
• shaving over a wart;
• nail biting that traumatises the skin around the nails.

Warts may not appear immediately after contact with the virus. Sometimes several months pass before a visible growth appears. Therefore, it is often impossible for the patient to identify exactly where and when the infection occurred.

What do warts look like?

Warts can look different. They may be skin-coloured, greyish, yellowish, brownish or slightly darker than the surrounding skin. The surface is often rough, grainy or thickened. Some warts are raised above the skin, while plantar warts may appear to grow deeper into the skin because of pressure.

Common signs include:

• a rough, raised skin growth;
• thickened skin surface;
• small dark dots on the surface of the wart;
• pain, especially on the sole of the foot;
• several similar warts in one area;
• a wart near the nail or under the nail edge;
• small, flat warts on the face, hands or forearms.

The dark dots in a wart are not “roots”. They are usually tiny thrombosed blood vessels. This sign is often seen in plantar warts and may help distinguish a wart from a corn, but the exact diagnosis, when needed, is made by a dermatologist.

Do warts have roots?

Patients often say that a wart has a “root”, but medically a wart is not a tumour with roots. A wart develops in the upper layer of the skin, but on the sole of the foot it may appear deeper because body weight presses it into the thickened skin.

The black dots in a wart are also not roots. They are usually tiny blood vessels with small clots. This explanation is important because attempts to “pull out the root” at home can lead to bleeding, infection, scarring and spread of the virus.

Types of warts

Warts are divided into several types according to their appearance and location. Different types of warts may differ in treatment complexity, recurrence risk and the discomfort they cause.

Common warts

Common warts most often appear on the hands, fingers, palms, around the nails, on the elbows or knees. They are usually rough, raised above the skin and may be skin-coloured, greyish or brownish.

Common warts are often seen in children and teenagers, but they can also occur in adults. They may appear as a single lesion or as several warts at the same time. If a wart is traumatised or scratched, the virus can be spread to nearby skin.

Plantar warts

Plantar warts develop on the underside of the foot — often on the heel, the forefoot or other areas that bear pressure while walking. They may look like a thickened patch of skin with a rough surface and dark dots.

Unlike warts on the hands, plantar warts often do not grow noticeably outward. Because of body-weight pressure, they may appear to be embedded in the skin. This is why plantar warts can hurt when walking, running or standing for a long time.

In plantar warts, the natural skin line pattern over the lesion is often interrupted or altered, whereas in a corn the skin lines often continue across the thickening. This sign is not enough for self-diagnosis, but it can help a specialist together with other signs.

Sometimes several plantar warts merge into a larger area. Such warts can be more difficult to treat and may require assessment by a dermatologist or another specialist.

Flat warts

Flat warts are less raised, smoother and often smaller than common warts. They may be skin-coloured, slightly pink, light brown or yellowish. They more often appear on the face, backs of the hands, forearms or legs.

Flat warts may sometimes be numerous and can spread in areas where the skin is traumatised, for example after shaving. Therefore, it is not recommended to shave directly over warts or mechanically irritate them.

Warts around the nails

Warts around the nails, or periungual warts, are located near the nail fold, under the nail edge or around the nail. They can be painful, interfere with nail care and sometimes affect nail growth.

These warts are more common in people who bite their nails, pick the skin around the nails or frequently injure this area. Warts around the nails can be more difficult to treat because the nail matrix and surrounding tissues must be protected.

Filiform warts

Filiform warts are narrow, elongated or thread-like warts that more often appear on the face, neck, around the mouth, nose or eyelids. They may be cosmetically bothersome and easily traumatised.

Lesions on the face should not be cauterised or burned at home, because there is a risk of scarring, pigmentation changes and incorrect self-diagnosis. The treatment approach for such lesions should be discussed with a dermatologist.

Genital warts

Genital warts are also associated with the human papillomavirus, but they are caused by other HPV types and have different transmission, diagnosis and treatment considerations. They are usually discussed as a separate sexually transmitted infection topic.

This article mainly focuses on common skin warts on the hands, feet, face, body and around the nails. If the lesions are located in the genital or anal area, a dermatologist, venereologist, gynaecologist or urologist should be consulted.

Warts in children

Warts are relatively common in children and teenagers. This is related to active contact in children’s groups, sport, minor skin injuries, walking barefoot in shared areas and particular features of the immune response.

Some warts in children can disappear on their own, but this may take time. Observation may be appropriate if the wart is small, painless, not spreading and does not cause the child discomfort. However, a dermatologist’s consultation is needed if the wart:

• hurts or interferes with walking;
• is located on the sole of the foot;
• is located on the face or near a nail;
• bleeds or is frequently traumatised;
• grows or spreads rapidly;
• is scratched or picked by the child;
• parents are not sure that it is truly a wart.

Children should not use aggressive treatments without a doctor’s or pharmacist’s advice, especially on the face, in sensitive areas, near nails or on unclear lesions. Inappropriate self-treatment may cause a burn, scar, pigmentation changes or skin irritation.

How to distinguish a wart from a corn, blister, mole or another skin lesion?

It is not always possible for a patient to determine safely whether a lesion is a wart. Different skin lesions can look similar, especially on the feet or in areas where the skin is thickened.

Wart or corn

A wart is a virus-induced skin growth. A corn is a thickening of the skin caused by mechanical pressure or friction. Both can be painful, especially on the foot.

A plantar wart is more often characterised by a rough surface, dark dots, interrupted skin line pattern and pain when the lesion is squeezed from the sides. A corn more often forms at a pressure point where footwear or foot biomechanics creates constant friction. However, these signs are not absolute, and accurate distinction can be made by a dermatologist or podologist.

Wart or blister

A blister usually develops after friction, for example from new or uncomfortable shoes, and is often filled with fluid. It tends to hurt when pressed directly from above and usually heals within a few days if friction is reduced.

A plantar wart is usually a denser, rougher skin lesion that may be painful when squeezed from the sides. Small dark dots may be visible on the surface of the wart, and the skin line pattern over the wart may be interrupted. If it is not clear whether the lesion is a blister, corn or wart, it should be shown to a dermatologist or podologist.

Wart or papilloma

Papillomas are often softer, skin-coloured, stalk-like growths that tend to occur on the neck, in the armpits, groin or eyelid area. Warts are usually rougher and denser. However, the difference is not always obvious, so an unclear lesion should be checked.

Wart or mole

Moles are usually pigmented or skin-coloured melanocytic lesions, whereas warts are HPV-induced epidermal growths. However, some warts can be brownish, and some moles can be raised above the skin. If a lesion changes colour, shape or size, bleeds or looks different from the others, it must not be removed or treated with caustic agents at home — a mole or skin lesion examination by a dermatologist is needed.

Wart or seborrhoeic keratosis

Seborrhoeic keratoses are common benign skin lesions in adults and older people. They may be rough, brownish, greyish or look as if they are “stuck on” the skin. Sometimes they can resemble a wart or a pigmented lesion. If the appearance is unclear, a dermatologist’s examination and dermoscopy can help.

Can warts turn into cancer?

Common skin warts on the hands, feet or body are most often benign growths and usually do not turn into skin cancer by themselves. However, it is important to understand that not every rough, bleeding or growing lesion is a wart. Some skin tumours or precancerous lesions can visually resemble a wart.

Therefore, a dermatologist’s examination is needed if a lesion grows rapidly, bleeds without a clear injury, ulcerates, becomes painful, changes colour or shape, or if there is uncertainty that it is truly a wart.

Genital warts and HPV-related mucosal infections are a separate topic, where diagnosis and risk assessment differ from common skin warts. In such cases, consultation with the appropriate specialist is needed.

When should a wart be shown to a dermatologist?

A wart or wart-like lesion should be shown to a dermatologist if:

• the lesion grows or changes rapidly;
• the colour, shape or surface changes;
• the lesion bleeds, ulcerates or forms a non-healing crust;
• the lesion is painful, tender or interferes with walking;
• the lesion is located on the face, near a nail, on the sole of the foot or in the genital area;
• there are several warts or they are spreading;
• the wart does not go away for a long time;
• the person has diabetes, impaired blood circulation in the feet or weakened immunity;
• there is uncertainty that the lesion is truly a wart.

It is especially important not to miss potentially dangerous skin lesions. If a lesion bleeds without a clear injury, ulcerates, grows rapidly, changes colour or shape, or looks atypical, it should not be treated at home as a “simple wart”. In these cases, a dermatologist’s assessment is needed.

How are warts diagnosed?

Wart diagnosis usually begins with a dermatologist’s examination. The doctor assesses the appearance and location of the lesion, the patient’s age, symptoms, how long the wart has been present, previous treatment and whether similar lesions are present elsewhere.

In many cases, a wart can be identified by its typical appearance. In unclear cases, the dermatologist may use dermoscopy — examination of the skin lesion with a special magnifying device and light source. Dermoscopy helps assess the structure of the lesion and distinguish a wart from a corn, mole, seborrhoeic keratosis or another lesion.

In rare or unclear cases, if the lesion is not typical or another diagnosis is suspected, the doctor may recommend removal of the lesion and histological examination. Histology is microscopic examination of a tissue sample in a laboratory.

Can warts go away on their own?

Yes, some warts can disappear on their own. This happens when the immune system recognises HPV-affected skin cells and gradually controls the infection. Spontaneous resolution is more likely in children and young people, but it can also occur in adults.

Observation may be appropriate if the wart is small, painless, not traumatised and not located in a place where it spreads easily or interferes with daily life. However, if it is on the sole of the foot, near a nail, on the face, in a child, in a person with weakened immunity or if the lesion is unclear, it is better not to wait too long and to consult a dermatologist.

The decision to observe or treat should be individual and should take into account the wart’s location, size, number, the patient’s age and any associated conditions.

Wart treatment — brief overview

The aim of wart treatment is to reduce symptoms, limit spread and remove the troublesome lesion. The choice of treatment depends on the type, location, size and number of warts, the patient’s age, skin characteristics, previous treatments and coexisting conditions.

Wart treatment options may include:

• observation;
• topical treatments;
• products containing salicylic acid;
• cryotherapy, or freezing;
• curettage;
• laser therapy;
• other methods chosen by the dermatologist.

In this article, treatment is described in general terms, because the detailed course of procedures, selection criteria and available options should be described on the related procedure page: Wart removal.

Topical treatments

For some small, typical warts, pharmacy products may be used, such as preparations containing salicylic acid. They help gradually break down the thickened top layer of skin over the wart. Such products should be used only according to the instructions.

They should not be used on the face, in the genital area, on bleeding, ulcerated, painful or unclear lesions. Special caution is needed in children, pregnant women, people with diabetes, peripheral circulation problems or immunosuppression.

When are home treatments not suitable?

Cryotherapy, or freezing

Cryotherapy is a method in which a wart is treated with a very low temperature. It damages wart tissue and helps the body gradually reject it. After the procedure, short-term pain, burning, redness, a blister or tenderness may occur.

The number of procedures and the interval between them depend on the type of wart, its location and its response to treatment. Plantar warts and warts around the nails may sometimes be more persistent.

Laser therapy and other procedures

In some cases, the dermatologist may recommend laser therapy, curettage or another method. Such procedures should be carried out only after the lesion has been assessed. This is especially important for the face, visible areas, lesions near the nails, the genital area and cases where the diagnosis is not completely clear.

Suspicious, pigmented, bleeding, ulcerated or rapidly changing lesions must not simply be removed for cosmetic reasons without diagnostic assessment.

When is wart removal needed?

Wart removal may be needed if the wart causes pain, spreads, is traumatised, interferes with walking, causes cosmetic concern or is located in an area where it is difficult to protect from mechanical irritation.

Removal is more often considered if:

• the wart is on the sole of the foot and painful;
• the wart is near the nail or under the nail edge;
• there are several warts;
• the warts are spreading;
• the wart interferes with sports, walking or work;
• the wart regularly bleeds after trauma;
• the wart causes psychological or cosmetic discomfort;
• previous treatment has not helped.

Read more about methods, procedure course and options in the related article: Wart removal.

Why do warts come back?

Warts may recur because removal of the visible lesion does not always mean that the body’s immune response has already fully controlled the effect of HPV in the surrounding tissues. Sometimes invisible virus-affected cells may remain, or the person repeatedly traumatises the skin and spreads the virus to nearby areas.

The risk of recurrence may be higher if:

• there are several warts;
• the warts have been present for a long time;
• the warts are on the feet or around the nails;
• the person scratches or picks at the warts;
• there is increased sweating of the feet;
• immunity is weakened;
• immunosuppressive therapy is used;
• preventive measures are not followed.

Wart recurrence does not mean that treatment was necessarily done incorrectly. Sometimes a longer strategy, a combined approach or several dermatologist visits are needed.

How to reduce the risk of wart spread?

The spread of warts can be reduced by protecting the skin and preventing the virus from reaching other skin areas or other people.

Recommendations:

• do not scratch, pick or cut warts;
• do not use the same nail file or scissors on healthy skin and on a wart;
• do not share towels, shoes or socks;
• wear flip-flops or shower shoes in swimming pools, gyms and shared showers;
• keep the feet dry;
• change socks regularly;
• do not walk barefoot in shared areas;
• do not shave directly over warts;
• in friction areas, a wart may be covered with a plaster;
• explain to children that warts must not be scratched or picked.

If the wart is already being treated, follow the doctor’s or product instructions for skin care and protection.

Wart prevention at home, in swimming pools, gyms and the family

It is not possible to completely prevent the risk of warts, because HPV is common and the virus may be present in the environment or on the skin. However, the risk can be reduced.

At home, use individual towels and nail-care instruments. If someone in the family has a plantar wart, shoes or socks should not be shared. In the bathroom and shower, hygiene should be maintained and long-lasting moisture should be avoided.

In swimming pools and gyms, flip-flops should be worn, especially in showers and changing rooms. After visiting these places, the feet should be dried, especially between the toes. People with increased foot sweating should choose breathable shoes and change socks regularly.

It is important to explain to children that warts should not be picked or scratched. If a child does sports or attends a swimming pool, foot protection in shared areas is especially important.

What should not be done to warts?

Warts should not be cut, picked, burned, tied with a thread, treated with unsuitable caustic agents or mechanically traumatised at home. Such actions can cause bleeding, infection, scarring, pigmentation changes and spread of the virus.

It is especially dangerous to treat a lesion at home if it is not clear whether it is truly a wart. A suspicious skin lesion may require a dermatologist’s examination, dermoscopy or histological examination. Incorrect self-treatment can delay the correct diagnosis.

Without a doctor’s assessment, the following should not be treated at home:

• lesions on the face;
• lesions on the eyelids;
• lesions in the genital area;
• bleeding or ulcerated lesions;
• rapidly growing lesions;
• pigmented or atypical lesions;
• foot lesions in people with diabetes or circulation problems;
• skin lesions in sensitive areas in children.

How to prepare for a dermatologist’s visit?

Before the dermatologist’s visit, it is useful to think about when the wart or lesion appeared, whether it has changed, whether it hurts, bleeds, itches, spreads or has been previously treated. If pharmacy products have been used, it is helpful to know their name or bring the packaging.

Before the visit, it is not advisable to treat the lesion aggressively, cut it, apply caustic agents or remove the thickened skin so intensively that it becomes harder for the doctor to assess the original appearance. If the lesion is on the foot, come to the appointment with clean, dry skin.

If there are previous photographs, medical records or dermoscopy images, they can be brought along. This helps assess changes over time.

How much does wart examination or treatment cost, and why can the price vary?

The cost of wart examination or treatment may vary depending on the type of doctor’s consultation, the number of lesions, their location, the required diagnostics, the chosen treatment method and the extent of the procedure.

The price may differ if only one typical lesion needs to be examined, if several warts need to be assessed, if dermoscopy is needed, if a procedure is performed or if repeated treatment is required. Plantar warts, warts near the nails and extensive or recurrent warts may require more time and a more individual approach.

The exact price should be checked in Medart’s current price list or clarified when booking the appointment. The course of procedures and treatment options are described in more detail on the related page: Wart removal.

Medical disclaimer

The information provided is for informational purposes only; it does not replace a dermatologist’s consultation, diagnosis or treatment. If a person notices a new, changing, bleeding, painful, ulcerated or otherwise suspicious skin lesion, or if there is uncertainty that the lesion is truly a wart, they should contact a dermatologist or the Medart clinic specialists listed below the article. A suspicious skin lesion must not be removed, burned, cut, tied, traumatised or treated at home with unsuitable products.

References and authoritative sources

• DermNet: viral warts, symptoms, types and treatment options
• DermNet: non-sexually acquired human papillomavirus infection
• American Academy of Dermatology Association: warts, patient overview
• American Academy of Dermatology Association: wart diagnosis and treatment
• American Academy of Dermatology Association: dermatologists’ advice for wart self-care
• National Health Service (NHS): warts and verrucas, spread, treatment and when to see a doctor
• Mayo Clinic: common warts, symptoms and causes
• Mayo Clinic: common warts, diagnosis and treatment
• Mayo Clinic: human papillomavirus infection and types of warts
• British Association of Dermatologists: plantar warts and their possible spontaneous resolution
• DermNet: anogenital warts and human papillomavirus
• Centre for Disease Prevention and Control of Latvia: infectious disease prevention and public health
• European Academy of Dermatology and Venereology: professional dermatology and venereology resources
• World Health Organization: human papillomavirus and public health
• Centers for Disease Control and Prevention: information on human papillomavirus

Author

Dermatologist Dr. med. Dace Buile