Condition

Warts

Warts are firm, rough growths caused by a common virus that infects the top layer of skin. They are harmless and most of them clear on their own, but they spread easily and they are slow to treat.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Warts. Never cropped: the tone strip and the corner logo depend on the full frame.

Start here

A wart is an infection, not a growth — the virus sits in the top layer of the skin, and every treatment we have is really a way of getting your own immune system to notice it. Warts are not a hygiene problem; the virus is common, it lives on wet floors and shared surfaces, and whether you get one comes down mostly to whether your immune system has met that strain before. The other thing I repeat all day is that treatment is slow, and stopping early is the single most common reason it fails. Soaking, filing and treating a wart every day for three months does more than an aggressive treatment done twice.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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How commonVery common - most people get at least one at some point, and they are a routine reason for dermatology visits
Who gets itMost often school-age children and teenagers. Also common in anyone whose immune system is suppressed by medicine or illness
Curable or managedCurable - once the immune system recognizes the virus the wart clears and usually does not come back in that spot
Prescription neededNot always. Over-the-counter salicylic acid clears many warts if it is used every day
Time to improveGive daily treatment two to three months before judging it. Untreated warts often take a year or more

What It Is

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A wart is a patch of skin infected by human papillomavirus, or HPV — a family of more than a hundred related viruses, a handful of which infect the skin of the hands, feet, face and knees. The strains that cause genital warts are different and are managed differently.

The virus infects keratinocytes, the cells of the outer layer of skin, and makes them divide faster than they should, piling up into a firm, raised bump with a rough surface, often compared to a tiny cauliflower. Because the growth sits in the outer layer only, a wart has no root and no seed; the black dots inside one are tiny clotted blood vessels. The fine lines of the skin, the ones that make a fingerprint, stop at the edge of a wart instead of running across it.

Warts look different depending on where they grow. Common warts are the classic rough, dome-shaped bumps on fingers, hands and knees. Periungual warts grow around and under the nails and are the most stubborn. Flat warts are small, smooth and barely raised, often in groups of dozens on the face, backs of the hands or shins, and spread easily by shaving. Filiform warts are the narrow, finger-like ones around the eyes, nose and mouth. Plantar warts grow on the soles and are pressed flat by body weight, which is why they feel like a stone in the shoe.

Warts are not dangerous and do not turn into skin cancer. People treat them because they spread to other spots and other people, catch on things, can be sore on the fingertips and feet, and are visible.

Symptoms

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Rough raised bumps

Common

Firm, rough-surfaced bumps with tiny black dots, most often on the hands, fingers and around the nails. They spread by touch and by picking. Most clear on their own, though it can take a year or more.
Small smooth spots in groups

Flat

Small, flat-topped, slightly raised spots that appear in groups of dozens, often on the face, backs of the hands or legs. Shaving spreads them in lines. They are easily mistaken for other bumps because they are so subtle.
Thread-like spikes

Filiform

Long, narrow, finger-like projections, usually on the face around the eyes, nose and mouth. They grow quickly and look different from other warts. They are usually removed rather than treated with creams.

How It Looks by Skin Tone

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A rough, dome-shaped wart on the side of a finger on fair skin. The bump is pinkish with a thin red ring at its base, and several tiny black dots are clearly visible in the thickened surface.A rough, thickened wart on the back of a hand on medium olive skin. It is much the same color as the skin around it, with only a faint pink rim, and the fine skin lines stop at its border.A firm, rough, gray-brown wart on the side of a finger on brown skin. There is no visible red ring around it, and the fine lines of the skin stop at the border of the bump.Two rough, thickened warts on the back of a hand on deep brown skin. They are the same brown as the skin around them with no red rim, and they are visible mainly by their raised, uneven surface.
LightMediumBrownDeep

On deeper skin tones warts are often the same color as the surrounding skin, or slightly gray or brown, and the ring of redness dermatologists look for is hard to see. So a wart gets mistaken for a callus, a corn or a mole, and treatment starts later than it should.

The bigger issue is the treatment. Freezing, called cryotherapy, works by injuring the skin, and injured skin on deeper skin tones commonly heals with a change in color. A pale ring can last a year or more and is sometimes permanent, and a dark mark, post-inflammatory hyperpigmentation, can outlast the wart by months. The same goes for anything that blisters or burns. That changes the trade-off rather than ruling these treatments out. Many dermatologists start with the slower, gentler options — daily salicylic acid, filing, paring in clinic — keep freezing shorter, and test one small wart before treating a group. Use sunscreen daily on treated areas on the face, hands or arms, because sun makes a dark mark deeper and slower to fade.

Where It Shows Up

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Front view of a whole body with red marks on both hands and fingers, on both knees and on both feet.
Fingers, hands, knees and feet
Warts land where skin gets knocked, wet or broken: the fingers, the backs of the hands, around and under the nails, the knees, and the soles and edges of the feet. Biting nails or picking skin spreads them along the finger.
Front view of a head with red marks around both eyes, on the nose, around the mouth and along the beard area of the jaw and chin.
The face, in a shaving path
Flat warts turn up in groups on the face, often spread in a line along a shaving path. The long, thread-like kind grow around the eyes, the nose and the mouth. They are the same virus, spread by the razor.

What Happens in the Skin

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This is what is going wrong under the skin, in the order it happens. Click a step to see it.

How Warts happens
Skin basics
BARRIEREPIDERMISDERMIS0NORMAL SKIN1THE VIRUS GETS IN2INFECTED CELLS MULTIPLY3THE IMMUNE SYSTEM HAS NOT RECOGNIZED IT YET

The outer layer sheds and replaces itself steadily. Small nicks and scrapes close over before anything can get in.

HPV needs a way through - a cut, a hangnail, a shaving nick, or skin softened by water. It reaches the dividing cells at the bottom of the outer layer and settles there.

The virus makes those cells divide faster than they should. They pile up into the rough, raised bump, with tiny clotted vessels showing as black dots.

HPV hides in the outer layer, where there is little blood supply and few immune cells patrolling. That is why warts last months or years, and why they eventually clear on their own once the immune system finds them.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Warts come from human papillomavirus, in four steps. First, the skin meets the virus. It survives well on warm wet surfaces — pool decks, locker room floors, shared showers, gym equipment — and passes by skin contact and on shared towels, razors and nail clippers. Second, it needs a way in. Intact skin blocks it, so it enters through a scratch, a hangnail, a shaving nick, a cracked heel, eczema, or skin wet long enough to lose its seal. Third, it infects cells in the outer skin layer and switches on their dividing machinery, so they multiply far faster than normal and pile into a thickened bump. Fourth, the immune system does not recognize the infection. HPV hides well — it stays in the outer layer, which has little blood supply and few immune cells, and makes proteins that quiet the local immune response.

That last step decides everything. Warts persist while the immune system has not identified the strain, and clear — sometimes all at once, overnight — when it does. It is why they are so common in children, who have met fewer strains, and stubborn in people on medicine that suppresses immunity.

There is usually a gap of one to six months between catching the virus and seeing a wart, which is why almost nobody can name where they picked it up.

Risk Factors

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Some people get warts repeatedly and others never do, and most of that is immune, not behavioral. This list is about exposure and how easily the virus gets in, not how clean anyone is.

Immune system
A weakened immune system
Transplant medicines, chemotherapy, long-term steroids and HIV make warts more numerous and harder to clear.
Immune system
Age
Children and teenagers get most warts, because their immune systems have met fewer HPV strains.
Immune system
Having had warts before
A history of warts predicts more, because it reflects how your immune system handles this virus.
Wet or broken skin
Skin that is often wet
Swimmers, hands in water all day, sweaty feet — a softened outer layer the virus gets through easily.
Wet or broken skin
Broken or cracked skin
Eczema, cracked heels, nail biting, hangnails and shaving all give the virus an opening.
Wet or broken skin
Handling raw meat and fish
Butchers, fish handlers and abattoir workers get more hand warts, from wet skin, small cuts and constant contact.
Shared spaces
Barefoot use of shared floors
Pool surrounds, locker rooms, communal showers, gym mats and dance studios.
Shared spaces
Living with someone who has warts
Shared towels, bath mats, razors, nail clippers and pumice stones move it around a household.

Course

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Warts are self-limiting — they end on their own eventually. In children, roughly two thirds clear within two years without treatment. Adults are slower, and warts present for several years are least likely to go quietly.

While it is activeOften months of no change
The wart sits still and seeds others

A wart can stay unchanged for months, and while it is active it seeds new ones nearby — in a ring around the original, or in a line along a shaving path or a scratch.

When it turnsA few weeks
Clearing is fast, not gradual

Once the immune system identifies the virus the wart clears over a few weeks, and several often go at once. That is why a wart can vanish after a treatment that should not have worked.

Signs it is clearingWhat to look for
The return of normal skin lines is the reliable sign

The bump flattens, the rough surface softens, the black dots disappear, and the fine lines of the skin start running across it again. If the surface is smooth but the lines still stop at the edge, virus is still there — keep treating another week or two.

After it clearsLong term
It rarely returns in the same spot

Immunity to that strain lasts, so new warts elsewhere are a different strain or a fresh exposure. In people on immune-suppressing medicine, warts recur far more often and are managed rather than cured.

What Makes It Better & Worse

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A wart takes four steps — contact with the virus, a break in the skin, infected cells multiplying into a bump, and an immune system that has not recognized it. Most of what spreads warts is mechanical, so nearly every line below either moves virus onto fresh skin or opens the skin for it.

What is driving yours?

FATBARRIEREPIDERMISDERMIS

HPV needs a way through - a cut, a hangnail, a shaving nick, or skin softened by water. It reaches the dividing cells at the bottom of the outer layer and settles there.

HPV needs a way through - a cut, a hangnail, a shaving nick, or skin softened by water. It reaches the dividing cells at the bottom of the outer layer and settles there.

The virus makes those cells divide faster than they should. They pile up into the rough, raised bump, with tiny clotted vessels showing as black dots.

What helps

  • Covering the wart Keeps virus off other spots and holds treatment against the skin.
  • Your own kit Flip-flops in shared showers, own towel, own clippers.

What makes it worse

  • Picking, biting and pulling at warts Carries virus to fingers and lips, and leaves broken skin for it.
  • Shaving over a wart Seeds virus along the whole shaving path.
  • Walking barefoot in shared showers Warm wet floors are where the virus survives longest.
  • Nail biting and picking at hangnails The most reliable way to get warts around the nails.
  • Sharing personal tools Towels, razors, nail clippers, pumice stones and files move the virus.
  • Reusing one file on several warts It spreads them between your own sites.

What helps

  • Keeping hands and feet dry Change socks during the day, dry between the toes, air your shoes.
  • Treating dry skin and eczema properly Intact, moisturized skin is much harder to enter.

What makes it worse

  • Skin that stays wet for hours The outer layer softens and stops being a seal.
  • Eczema, dry skin and cracked heels Broken skin is an open door.

What helps

  • Salicylic acid, used every single day Dissolves the infected thickened skin a layer at a time.
  • Filing between treatments Lets the next dose reach live infected skin instead of a crust.
  • Freezing in clinic, called cryotherapy Liquid nitrogen destroys infected skin, every two to four weeks.
  • Home freeze kits Best on small, new, thin warts, and not as cold as liquid nitrogen.
  • Cantharidin, applied in clinic A blistering agent, painless going on, so it suits children.
  • Duct tape Cheap and harmless, but the evidence is mixed — no substitute for salicylic acid.
  • Give any treatment 12 weeks Most people who say salicylic acid did not work used it about ten days.

What makes it worse

  • Stopping treatment too early Virus stays at the edges a week or two after the surface looks normal.

What helps

  • Immune-based treatments Imiquimod cream or candida antigen injections for warts that keep returning.

What makes it worse

  • Medicines that suppress the immune system Warts get more numerous and much slower to clear.

How These Treatments Work

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Treatments for Warts do not all work in the same place. Tap one to see where it acts.

Pick a treatment
Skin basics
BARRIEREPIDERMISDERMISREMOVES INFECTED SKINFREEZES ITWAKES THE IMMUNE SYSTEMSTOPS IT SPREADINGMOST CLEAR ON THEIR OWN

Takes off the layers where the virus lives, a little at a time. It needs months.

Destroys the tissue, and the blister that follows draws the immune system in.

A wart clears when the immune system finally recognizes the virus.

To other places on you, and to other people.

Usually within one to two years, with no treatment at all.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Over-the-Counter Products

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Everything here you can buy without seeing anyone.

Paula's Choice 2% BHA exfoliant, La Roche-Posay Effaclar cleanser and a CeraVe psoriasis cream pumpLabeled cutaway diagram of a single skin pore, headed Salicylic Acid. The epidermis is a brick-textured band across the top and the dermis is pink below it, with a yellow oil gland at the base of the pore and a small cluster of bacteria inside it. A single dark navy callout line points into the top of the pore: decreases dead cells in pore. There are no other callouts, so the drawing shows one effect where the other ingredient diagrams show two or three.
Strong evidence
The first treatment for almost every ordinary hand or foot wart, and the one with the best evidence outside the clinic. It dissolves the infected thickened skin a layer at a time, so it only works if it goes on every single day. Soak the wart for five minutes, file the dead surface off, apply, and cover it. Twelve weeks is a fair trial; ten days is not.
Soaking and filing
Soaking and filing
Moderate evidence
Not a treatment on its own, but the thing that makes salicylic acid work. Filing the dead crust off between doses lets the next dose reach live infected skin instead of sitting on top of it. Use a file or pumice kept only for that wart and thrown away afterwards, because one file used on several warts spreads them between your own sites.
Home freeze kits
Home freeze kits
Moderate evidence
The pharmacy sprays get nowhere near as cold as clinic liquid nitrogen, so they work best on small, new, thin warts on the hands and poorly on thick foot warts. They sting and can blister. On deeper skin tones they carry the same risk of leaving a pale or dark mark as clinic freezing does.
Duct tape
Duct tape
Weak evidence
Covering a wart with tape for a few days at a time, then filing it, is cheap and harmless, and the trials are genuinely mixed on whether the tape itself adds anything. Any benefit is probably from the covering and the filing. It is reasonable alongside salicylic acid and a poor substitute for it.

Prescriptions

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These need a prescription.

A white cream tube lying on its side on a white background, with a plain white label reading Imiquimod and a blue swoosh beneath it.
Imiquimod cream
Limited evidence
A cream that works on the last step of the problem: it makes the local immune system pay attention to the virus. It is used mainly for flat warts on the face and for warts that keep coming back, applied a few nights a week for weeks. It reddens and irritates the skin while it works, and it does poorly on thick foot warts.
A plain white medicine tube lying at an angle on a white background, capped, labeled Tretinoin in black with a navy blue swoosh curving along its length.Diagram: how Tretinoin works in the skin
Limited evidence
A retinoid cream used for the flat warts that appear in groups of dozens on the face and the backs of the hands, where acid and freezing would be too harsh over so wide an area. It speeds up the turnover of the infected surface cells. It takes months, and it makes the skin dry and sun-sensitive while it runs.
A white cream tube lying on its side on a white background, with a plain white label reading Fluorouracil and a blue swoosh beneath it.
5-fluorouracil cream
Limited evidence
A chemotherapy cream at a low strength, applied to the wart itself, often under tape. It is used for flat warts and for warts that have not shifted with acid, and it is a common choice in children because it does not hurt going on. It reddens and can crust the treated skin, and it is not used in pregnancy.
An amber prescription bottle lying on its side on a white background with a plain white label reading Cimetidine, and six small round white tablets spilled out in front of it.
Cimetidine
Weak evidence
An old stomach-acid tablet that people ask about for multiple stubborn warts, on the idea that it nudges the immune system. The better-controlled trials found it no more effective than a dummy tablet in adults. It is safe and cheap, so it is occasionally still tried in children, but it should not replace treatment that is known to work.

Procedures

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These are done in the office, usually over several visits.

16:9 hero for Cryotherapy (Liquid Nitrogen). Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Cryotherapy (Liquid Nitrogen) works in the skin
Strong evidence
Liquid nitrogen freezes the infected skin and the injury also draws immune attention to the spot. It needs repeating every two to four weeks, usually three or four times, and a wart regrowing from the edge between sessions is normal rather than failure. Over several months its results are broadly similar to salicylic acid used properly. It stings, it blisters, and on deeper skin tones it can leave a lasting pale or dark mark.
16:9 hero for Cantharidin. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Cantharidin works in the skin
Moderate evidence
A blistering liquid painted on in clinic and washed off a few hours later. It is painless going on, which is why it is a common first choice for children and for warts on the face. The blister that follows lifts the infected skin away over the next few days and can be sore. It usually takes more than one visit.
Paring in clinic
Moderate evidence
The top dead layer is shaved off with a blade. It does not hurt, because that layer has no nerve supply, and it does two jobs at once: it confirms the diagnosis by exposing the tiny clotted vessels a callus does not have, and it lets acid or liquid nitrogen reach live infected skin. It is done alongside another treatment, never as the whole treatment.
Candida antigen injection
Moderate evidence
A tiny amount of yeast protein injected into one wart, to wake the immune system up in that spot. What makes it useful here is that untreated warts elsewhere on the body often clear at the same time, so it suits someone with many warts rather than one. It is repeated every few weeks, and it can cause a day or two of aching or flu-like feeling.
Bleomycin injection
Moderate evidence
Injected directly into warts that have resisted everything else, particularly thick ones on the soles and around the nails. Clearance rates are good. It is painful enough that the area is numbed first, it can leave a permanent nail change if used at the nail fold, and it is not used in pregnancy, so it sits late in the order for a reason.
A gloved clinician treating a small dark spot on a patient's shoulder with a fine handheld instrument16:9 hero for Electrodesiccation and Curettage. Never cropped: the tone strip and the corner logo depend on the full frame.
Limited evidence
The wart is numbed, burned with an electric current and scraped away in one visit. It is kept for a single stubborn wart that has failed everything gentler, because it leaves a scar, and a scar on the sole of a foot can hurt more than the wart did. Warts can still regrow at the edge of the scar.
A patient in protective goggles lying under a large laser head positioned over their face16:9 hero for Pulsed Dye Laser (V-Beam). Never cropped: the tone strip and the corner logo depend on the full frame.
Limited evidence
The laser targets the small blood vessels feeding the wart rather than the virus itself. It is an option for stubborn warts on the hands and around the nails when freezing has not worked, and it spares the skin around it, which matters on the face. Several sessions are needed, results are inconsistent, and it is not usually covered by insurance.

When to See a Dermatologist

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Most warts never need a dermatologist; home treatment handles the majority. Book if a wart is painful, bleeding, or getting in the way of walking or using your hands, if warts are multiplying, if they are around or under the nails or on the face, if three months of daily home treatment has changed nothing, or if you take medicine that suppresses your immune system. Two things deserve a faster appointment. If you have diabetes or reduced sensation in your feet, do not treat a foot wart at home — acid and blades on a foot that does not feel pain well can leave a wound that heals slowly. And a single rough growth in an adult that keeps growing, bleeds easily, or has an odd shape or color should be examined, because a few skin cancers look very much like one.

— Dr. Schwarz, Board Certified Dermatologist

Complications

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Spreading to new spots

An untreated wart seeds others nearby, so one bump becomes a ring of small ones around it, or a line of them along a scratch or a shaving path. Picking, biting and filing several warts with the same file are the usual ways it happens. Covering the wart, keeping your own file and treating early keep the number down.

Color change after treatment

Freezing, and any treatment that blisters or burns, works by injuring the skin, and injured skin can heal a different color. A pale ring around the treated spot can last a year or more and is sometimes permanent, and a dark mark can outlast the wart by months. Both are far more likely on deeper skin tones, which is why gentler treatment and a small test spot are often the better trade.

Warts around and under the nails

Warts that set up in the nail folds are the most stubborn of the group, because the nail shields the virus from creams and from freezing. Left long enough, a wart growing under the nail can lift it or leave a permanent ridge or split in the nail plate. Nail biting and picking at hangnails are how most of them start, and they are the ones most worth taking to a dermatologist early.

Lookalikes

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Corns and calluses

The confusion that matters most on the feet, because the treatments are different. Both are thick and hard, but a corn or callus pares down to smooth, even skin with the fine skin lines running straight across it, while a wart pares down to tiny black or dark red dots and the skin lines stop at its edge. A callus also sits exactly where a shoe presses, and it hurts on direct pressure rather than on a squeeze from the sides.

Seborrheic Keratosis

A harmless age-related growth that is rough and warty enough to be taken for a wart, and it is often called one. It looks stuck onto the skin like a blob of wax, its color runs from tan to almost black, and its surface has visible plugged openings rather than clotted vessel dots. It also appears from middle age on the trunk and face, whereas ordinary warts favor the hands and feet of younger people.

Squamous Cell Carcinoma

The reason a single stubborn growth in an adult should be looked at rather than treated blindly. This skin cancer can be rough and raised enough to pass for a wart. The differences are that it is usually one growth rather than several, it keeps growing rather than sitting still, it often bleeds or crusts and does not heal, and it turns up on sun-exposed skin in older adults. Warts are commoner in children and tend to come in groups.

Myths

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  • "Warts have roots that have to be dug out." They do not. A wart sits entirely in the outer layer of skin, and the black dots people take for roots are tiny clotted blood vessels. Cutting deeper only leaves a scar.
  • "Warts come from touching frogs or toads." Warts come from a human virus that only infects human skin.
  • "Warts mean you are dirty." They have nothing to do with how clean you are. The virus is common, and who gets a wart is mostly about which strains their immune system has already met.
  • "Freezing is the strongest treatment, so it must be the best." Freezing is faster in the clinic, but over months its results are broadly similar to salicylic acid used properly at home. It is also painful, and on deeper skin tones it risks leaving a pale or dark mark. One good option, not the top of a ladder.
  • "Once the bump is flat, it is gone." Virus stays at the edges a week or two after the surface looks normal. The signal to stop is the fine lines of the skin running across the spot again.
  • "If I leave it alone it will spread everywhere." Most warts stay as a few, and most clear on their own within a couple of years in children. Picking drives spread far more than leaving them alone.
  • "Warts can turn into skin cancer." Ordinary hand and foot warts do not. But some skin cancers look like a wart, which is why a single stubborn growth in an adult that bleeds or keeps growing should be examined rather than treated blindly.

Questions Patients Ask

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How did I catch this?

Almost nobody can say. The virus lives on warm wet surfaces and passes by skin contact and shared objects, and there is usually a gap of one to six months between catching it and seeing the wart. It is not a sign of poor hygiene.

Will it go away if I just ignore it?

Probably, eventually. About two thirds of warts in children clear within two years without treatment, and adults are slower. Treating is worth it because warts spread to other spots and other people meanwhile, and older ones are harder to clear.

Why is my wart coming back after freezing?

Freezing removes infected skin but does not reach every infected cell, and it does not teach the immune system to recognize the virus. That is why it takes several sessions two to four weeks apart, and why a wart can regrow from the edge. Regrowth is normal, not treatment failure.

Are warts contagious to my family?

Yes, though not dramatically. The virus passes on shared towels, bath mats, razors, nail clippers and files, and through contact with broken skin. Keeping the wart covered, keeping your own towel and clippers, and wearing something on your feet in shared bathrooms covers most of the risk.

Is a wart on my hand the same as a genital wart?

Related viruses, but not the same strains, and they do not usually move between those sites. Genital warts are assessed and treated differently, so do not manage them with hand-wart products.

Can I cut it off myself?

No. A wart has no root to remove, so cutting reaches live skin without reaching all the virus, and you are left with a scar plus a wart growing back around it. It also risks infection and, on the foot, a wound that heals slowly. Paring is done in clinic with a sterile blade.

References

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