Warts: Causes, Types, Symptoms, Diagnosis, Treatment and Prevention

What Are Warts?

Warts are common, benign skin growths caused by infection with certain types of the human papillomavirus (HPV). The virus infects the outer layer of the skin and causes skin cells to grow more rapidly, resulting in the formation of a rough or raised growth.

Warts can affect people of all ages, but they are particularly common among children and teenagers. They may appear on different parts of the body, especially the hands, fingers, feet, and face.

Most common skin warts are harmless and may disappear without treatment, although this can take several months or even years. Some warts, particularly those on the soles of the feet, can become painful because of pressure from walking.

There are more than 100 known types of HPV. Different HPV types are associated with different types of warts and infections. More information about HPV and the health conditions it can cause is available from the Centers for Disease Control and Prevention (CDC).

Important: A skin wart is not the same as a genital wart. Genital warts are also usually benign, but they are caused by specific HPV types that are transmitted primarily through sexual contact.

Types of Warts

Warts can develop almost anywhere on the skin. Their appearance varies depending on the HPV type and the location of the infection.

1. Common Warts

Common warts, also called verruca vulgaris, usually appear on the hands, fingers, and around the fingernails.

They typically appear as:

Rough, firm, skin-colored or grayish bumps
Raised growths with an uneven surface
Small dark dots that may be visible within the wart

These dark dots are usually small blood vessels that have become clotted or thrombosed and are sometimes mistaken for seeds, which is why common warts are occasionally called “seed warts.”

Common warts may be more frequent in people who bite their nails or pick at the skin around their nails because small breaks in the skin can make it easier for the virus to enter.

2. Plantar Warts

Plantar warts develop on the soles of the feet and sometimes on the underside of the toes.

Unlike many other warts, plantar warts may grow inward because of the pressure exerted on them while standing and walking. They can therefore appear flatter and may cause pain or tenderness.

Some plantar warts occur in groups and are called mosaic warts.

Typical features include:

Thickened skin over the wart
Small dark dots
Pain when walking or standing
A rough or irregular surface

3. Flat Warts

Flat warts, also known as verruca plana, are smaller and smoother than common warts.

They may be:

Skin-colored, pink, or light brown
Flat or only slightly raised
Numerous, sometimes appearing in dozens of lesions

Flat warts commonly occur on the face, forehead, hands, arms, and legs. In children and young adults, they may spread through scratching, shaving, or other forms of minor skin trauma.

4. Filiform Warts

Filiform warts are thin, elongated growths that may look like small threads or projections from the skin.

They commonly occur on the:

Face
Around the mouth
Nose
Eyelids and areas around the eyes

They can grow relatively quickly and may be noticeable because of their location.

5. Genital Warts

Genital warts are caused by certain types of HPV and are primarily transmitted through sexual skin-to-skin contact.

They may appear around the:

Penis and scrotum
Vulva and vagina
Cervix
Anus and surrounding skin

They can be small or large, flat or raised, and may occur individually or in clusters.

It is important to understand that genital warts themselves are generally benign. However, HPV includes both low-risk types that commonly cause genital warts and high-risk types that can contribute to certain cancers. The HPV types that usually cause genital warts are different from the types most strongly associated with cancer.

What Causes Warts?

Warts are caused by infection with certain types of human papillomavirus (HPV).

The virus can enter the skin through small cuts, scratches, cracks, or other minor injuries. Once inside the skin, HPV can cause the infected cells to multiply, leading to the development of a wart.

The virus can spread through:

Direct skin-to-skin contact
Contact with an infected wart
Sharing personal items such as towels, razors, or nail tools
Picking, scratching, or biting a wart and then touching another part of the body
Walking barefoot in some shared, moist environments, particularly in the case of plantar warts

HPV does not always cause a visible wart immediately. A wart may take weeks or months to become noticeable after infection.

Who Is More Likely to Develop Warts?

Anyone can develop warts, but some people are more susceptible than others.

Warts are particularly common among:

Children and teenagers
People who bite their nails or pick at their skin
People with frequent minor cuts or skin injuries
People who frequently use communal showers, swimming pools, or changing rooms
People with a weakened immune system
Individuals with certain chronic medical conditions that affect immunity

A weakened immune system may make it more difficult for the body to clear the HPV infection, resulting in persistent or recurrent warts.

Are Warts Contagious?

Yes. Warts can spread through close skin contact or contaminated surfaces, particularly when the skin is wet or damaged. Simple measures such as washing hands, avoiding picking at warts, and not sharing personal items can help reduce transmission.

However, transmission does not necessarily occur every time someone comes into contact with a wart. The virus is more likely to enter the skin when there are small cuts, cracks, or other areas of damaged skin.

To reduce the risk of spreading warts:

Avoid picking or scratching warts.
Do not bite fingernails or the skin around them.
Do not share towels, razors, nail clippers, or other personal items.
Wash your hands regularly.
Keep warts covered when appropriate.
Avoid shaving directly over a wart.
Do not use the same nail file or pumice stone on a wart and healthy skin.

How Are Warts Diagnosed?

Most warts can be diagnosed by a dermatologist through a physical examination.

In most cases, a dermatologist can diagnose a wart by examining it. If a lesion grows rapidly, looks unusual, or does not respond to treatment, a skin biopsy may sometimes be needed to rule out other skin conditions.

A skin biopsy may occasionally be recommended when the diagnosis is uncertain, the lesion has an unusual appearance, grows rapidly, bleeds, or does not respond to appropriate treatment. A biopsy can help distinguish a wart from other skin conditions.

When Should You See a Doctor?

Although most warts are harmless, you should seek medical evaluation if:

You are not sure whether the growth is actually a wart.
The lesion changes in appearance.
It becomes painful, itchy, or starts bleeding.
It grows rapidly.
There are many warts.
The wart is located on the face or genital area.
The wart does not improve despite appropriate treatment.
You have diabetes or poor circulation.
You have a weakened immune system.
The lesion repeatedly returns after treatment.

These situations may require a professional diagnosis and a more appropriate treatment plan.

Can Warts Be Prevented?

There is no way to prevent every wart, but several measures can reduce the risk of infection and transmission.

Practical prevention measures include:

Avoid direct contact with another person’s wart.
Keep cuts and scratches clean and covered.
Avoid picking, scratching, or cutting warts.
Do not share towels, razors, nail clippers, or personal grooming tools.
Keep feet clean and dry.
Wear appropriate footwear in communal showers and changing rooms.
Wash your hands regularly.
Avoid shaving over areas affected by warts.

For genital HPV infections, safer sexual practices can reduce the risk of transmission. Condoms can lower the risk but cannot provide complete protection because HPV can infect areas of skin that are not covered by a condom.

HPV Vaccination

The HPV vaccine is an important method of preventing infection with several HPV types, including types associated with genital warts and certain cancers.

The vaccine is designed primarily to prevent new HPV infections. It does not treat an existing HPV infection or remove an existing wart. Vaccination is most effective when given before exposure to HPV, although eligibility and recommendations vary according to age and individual circumstances.

People should discuss HPV vaccination with their healthcare provider to determine the appropriate vaccination schedule based on their age and medical history.

Treatment of Warts

Many non-genital warts eventually disappear without treatment as the immune system recognizes and clears the infection. However, this process may take months or even years.

Treatment may be recommended when:

The wart is painful.
It is spreading or increasing in number.
It is located in a troublesome area.
It causes cosmetic concerns.
It repeatedly returns.
There is a risk of spreading it to other people or other parts of the body.

No single treatment is effective for every wart. The choice depends on the type, size, location, number of warts, age of the patient, and other medical factors.

1. Salicylic Acid

Salicylic acid is one of the most commonly used treatments for common and plantar warts.

It works by gradually removing the layers of the wart.

Depending on the product and medical advice, treatment may involve:

Soaking the wart in warm water to soften it.
Carefully drying the area.
Applying the salicylic acid directly to the wart according to the product instructions.
Repeating treatment regularly for several weeks.

The surrounding healthy skin should be protected from unnecessary irritation.

People with diabetes, poor circulation, or reduced sensation in the affected area should consult a healthcare professional before using salicylic acid products.

2. Cryotherapy

Cryotherapy is a common treatment performed by a dermatologist using an extremely cold substance, usually liquid nitrogen.

The freezing process destroys the wart tissue. A blister or crust may develop afterward, which is generally part of the healing process.

Several treatment sessions may be required, often at intervals of a few weeks.

Possible side effects include:

Temporary pain
Blistering
Skin discoloration
Rarely, scarring

3. Cantharidin

Cantharidin is a treatment applied by a healthcare professional to certain types of warts.

It causes a controlled blister to form beneath the wart, helping separate the wart tissue from the skin.

Some discomfort, blistering, and temporary changes in skin color may occur.

Cantharidin should not be applied at home without professional guidance, as inappropriate application can cause significant skin irritation or chemical injury.

4. Electrosurgery and Curettage

For selected persistent warts, a dermatologist may use electrosurgery, sometimes combined with curettage.

The area is usually numbed first. The wart is then destroyed and/or removed using specialized medical instruments.

This approach can be effective for certain stubborn warts, although there is a risk of temporary discomfort, bleeding, infection, or scarring.

5. Other Treatments for Persistent Warts

When warts do not respond to standard treatments, a dermatologist may consider other options depending on the patient’s condition.

These may include:

Laser therapy
Prescription topical medications
Immunotherapy
Trichloroacetic acid
Intralesional treatments
Other specialist treatments for resistant warts

The choice should be made by a dermatologist after evaluating the wart and the patient’s medical history.

Treatment of Genital Warts

Genital warts require a different approach from ordinary skin warts.

Treatment options may include prescription medications such as imiquimod or podofilox for appropriate external lesions, as well as procedures such as cryotherapy, surgical removal, electrocautery, or laser treatment.

Over-the-counter wart medicines intended for hands and feet should not be used on genital warts because the genital skin is more sensitive and requires different treatment.

Treatment removes visible warts but does not necessarily eliminate HPV from the body. As a result, genital warts may recur after treatment, particularly during the first few months.

Do Warts Always Come Back?

Not necessarily.

Many warts disappear completely and never return. However, recurrence can occur because treatment removes the visible wart but may not immediately eliminate HPV from the surrounding skin.

Recurrence is particularly relevant with genital warts, where the virus may remain present even after visible lesions have disappeared.

Frequently Asked Questions About Warts

Are warts dangerous?

Most ordinary skin warts are harmless and do not develop into cancer. However, any unusual, rapidly changing, bleeding, or persistent skin growth should be examined by a doctor rather than assuming it is a wart.

Can warts disappear without treatment?

Yes. Many warts eventually disappear without treatment as the immune system clears the infection. However, spontaneous resolution can take months or even years.

Can I remove a wart myself?

Some small common or plantar warts can be treated with over-the-counter salicylic acid products when used correctly. However, self-treatment is not appropriate for every patient or every location.

Warts on the face or genital area, rapidly changing lesions, painful or bleeding lesions, and warts in people with diabetes or weakened immunity should be assessed by a healthcare professional first.

Can warts spread to other parts of the body?

Yes. Picking, scratching, shaving over a wart, or using contaminated grooming tools can contribute to spreading the virus to other areas.

Are genital warts the same as skin warts?

No. Both are caused by HPV, but different HPV types are usually responsible. Genital warts are generally benign, while certain other high-risk HPV types are associated with cancers.

When to Consult a Dermatologist

If you notice a new skin growth and are unsure whether it is a wart, professional evaluation is the safest approach.

You should especially consult a dermatologist if the lesion:

Changes rapidly
Bleeds
Becomes painful
Looks unusual
Does not respond to treatment
Keeps returning
Appears on the face or genital area
Is associated with numerous other lesions

Accurate diagnosis is important because several other skin conditions can resemble warts.

Conclusion

Warts are common viral skin growths caused by certain types of human papillomavirus (HPV). Most are benign and may disappear naturally, but some can persist, become painful, or spread to other areas of the body.

Treatment depends on the type and location of the wart and may include salicylic acid, cryotherapy, cantharidin, electrosurgery, curettage, laser therapy, or other specialist treatments.

Early medical evaluation is recommended when a skin growth is unusual, painful, bleeding, rapidly changing, persistent, or located in a sensitive area. A dermatologist can confirm the diagnosis and recommend the safest and most effective treatment.

Medical Disclaimer: This article is provided for general health education and does not replace a medical examination, diagnosis, or individualized treatment plan. If you have a persistent or unusual skin lesion, consult a qualified dermatologist or healthcare professional.

See : Dermatology

Warts