What Causes Corns on the Feet? How to Treat Them and How They Differ from Plantar Warts, by a Dermatologist
A corn (clavus) is a small, sharply bordered lump of thickened outer skin, about 3–10 millimetres across, shaped like a cone with a hard core pointing deep into the skin. It is caused by repeated pressure or friction on the same spot over a bony prominence. It is not an infection, and it has no "root" despite the common belief. Corns are most often found on the toes and soles, but they can also develop on the hands and fingers in people who repeatedly grip tools or equipment, and they hurt sharply when pressed straight down.
In the clinic, almost every patient with a corn asks the same four questions: what causes it · is it a problem if I leave it · do I need surgery · how many days until it heals. This article answers all four, explains how to tell a corn from a callus and from a plantar wart (which are treated differently), and covers corns on the hands, which most articles skip.
What is a corn, why does it hurt, and does it have a root?
Skin has a built-in defence: when it is pressed or rubbed repeatedly, it makes more keratin to withstand the force. If the force is spread over a wide area, the skin thickens into a broad patch called a callus. If the force is concentrated on one small point over a bony prominence, the keratin is packed into a hard, cone-shaped core pointing inward. That is a corn.
Why it hurts The hard core acts like a pebble embedded in the skin. Every time you put weight on it or a shoe presses on it, the core pushes down on nerve endings and the tissue beneath, causing a sharp, localised pain. Some people compare it to stepping on a stone all the time.
Does a corn have a root? No. The clear whitish spot in the middle that many people call the root is the most tightly packed keratin, made of dead skin cells. It is not living tissue and it does not "root" into the flesh. A corn that comes back after removal has not returned because part of the root was left behind. It returns because the pressure on that spot is still there, so the skin keeps rebuilding keratin in the same place. This is the most important point of all, because it is why treating a corn means fixing the pressure, not just removing the lump.
How to tell a corn, a callus and a plantar wart apart
All three are hard bumps on the foot, but they are different conditions with different causes and different treatments. The distinctions that work in practice are as follows.
Corn A small lump with a sharp border, 3–10 millimetres, with a hard, clear whitish core in the middle. It sits over a bony prominence such as the top of a toe, the tip of a toe or under the base of a toe. There is usually one or a few. It hurts a lot when pressed straight down. The skin lines are still visible around the lump. It is not contagious.
Callus A broad patch of thickened skin with an indistinct border and a pale yellow colour. There is no core. It appears over wider weight-bearing areas such as the heel, the ball of the foot and the side of the big toe. It is usually painless or causes a dull ache when very thick. It is not contagious.
Plantar wart Caused by the HPV virus. The surface of the wart shows several tiny black dots (clotted capillaries). The skin lines are interrupted at the wart. It hurts more when squeezed from the sides. There may be several, and they can merge into a plaque. It can appear anywhere and does not need to sit over a bony prominence. It is contagious through wet floors and shared items.
Simple tests you can do at home
Squeeze from the side versus press straight down. A wart hurts when squeezed; a corn hurts when pressed.
Look at the skin lines. Skin lines run through or around a corn or callus, but they are interrupted on a wart.
Look for black dots. A wart shows several tiny black dots when some of the surface is pared away. A corn has a single clear core in the middle.
Count and note the location. A single lump over a bony prominence pressed by a shoe points to a corn. Several scattered lumps, or a child, point to a wart.
If you are still not sure, do not use corrosive treatments or cut it yourself. Treating a wart means destroying virus-infected cells, while treating a corn means fixing the pressure, and the wrong approach wastes months. For more detail on telling the different types of warts apart, read What causes warts, how to tell the 5 types apart, and how plantar warts differ from corns
Hard corn, the most common type
Appearance A hard, dry lump with a smooth, shiny surface, yellow or grey, 3–10 millimetres, with a clear core in the middle. It forms on dry skin that is pressed from outside. Typical spots are the top of the joints of the fourth and fifth toes, the tips of the toes and under the heads of the metatarsal bones at the base of the toes.
Cause Tight or narrow shoes pressing on the toe joints, deformed toes whose joints bend upward against the shoe, or certain metatarsal bones carrying more weight than others.
Severity/urgency Not urgent in most people, but it can be painful enough to change the way you walk. Left for a long time, the skin beneath the core can become inflamed, bleed under the thick layer or break down into an ulcer.
When to see a doctor Pain that makes walking difficult, no improvement after 2–3 weeks of self-care, dark red colour or blood under the lump, or having diabetes or leg circulation disease.
Soft corn between the toes
Appearance A whitish, soft, mushy bump, like skin soaked in water for too long. The surrounding skin is macerated and may smell. It is most common in the web space between the fourth toe and the little toe. It hurts more than its size suggests, and sometimes cracks into a fissure or a small sore.
Cause The bony prominences of two neighbouring toes press against each other in a narrow shoe, combined with sweat moisture between the toes that cannot escape. The skin thickens but stays so wet that it becomes soft. People with very sweaty feet get them more easily and they are slower to clear. Read more about moisture and foot odour in Smelly feet and excessive foot sweating: causes and treatment
Severity/urgency Higher than a hard corn, because macerated skin is easily infected by bacteria or fungus, and sores between the toes heal slowly because the two toes rub together all the time.
When to see a doctor Cracks, weeping, pus, redness spreading from the toe web, or no improvement after 2 weeks of using a toe separator and wide shoes. Do not use acid patches in this location, because macerated skin burns easily.
Seed corn
Appearance Small hard bumps 1–3 millimetres across, with several scattered over the sole or heel, often in areas that do not bear weight directly. Most are painless or cause mild discomfort like a grain of sand stuck to the foot.
Cause Linked to very dry foot skin and repeated light friction more than to pressure from a bony prominence. One theory is that they come from sweat ducts blocked by keratin. They often occur together with dry, cracked skin and cracked heels.
Severity/urgency The lowest of the three types. Most improve with more moisture and urea cream.
When to see a doctor One of the bumps grows and becomes clearly painful, shows black dots, or does not fade after 4 weeks of regular moisturising, to rule out an early plantar wart.
Where corns appear on the foot and what the location tells you
The location of a corn on the foot is an important clue to where the pressure is coming from. Doctors use it to plan how to fix the underlying cause.
Appearance It differs by location, and each location points to a different underlying cause.
Top of the little toe or fourth toe joint Narrow shoes pressing from above or the side, or a deformed, bent toe.
Tip of the toe The toe is bent so the tip digs into the ground, or the shoe is so short that the toe hits the end. Common in runners and people who wear high heels.
Under the base of the toes or under the ball of the foot One metatarsal bone is longer or lower than the others, flat feet, high arches, or the fat pad under the sole thinning with age.
Inner side of the big toe or under the base of the big toe Often linked to a bunion pushing the bony prominence out against the shoe.
Heel This area usually develops calluses rather than corns. If it is thick and dry enough to crack into fissures, read Why do heels crack, and how to heal them
Cause Every location has the same common factor: a bony prominence and a hard surface pressing against each other repeatedly, thousands of steps a day. The only difference is whether the force comes from the shoe or from the structure of the foot itself.
Severity/urgency A corn under the weight-bearing sole hurts more and is more likely to break down into an ulcer than a corn on top of a toe, especially in people with underlying conditions.
When to see a doctor A corn under the sole that returns to the same spot every time even after changing shoes is a sign of a structural bone driver that needs to be examined.
What causes corns on the hands and fingers?
Corns do not occur only on the feet. They can occur on the hands by the same mechanism, repeated pressure or friction on the same spot. On the hands, however, a broad callus is more common, and it is a corn only when the force is concentrated over a bony knuckle.
Appearance A sharply bordered hard bump, smaller than on the feet, usually on the back of a finger joint, the side of a finger, a fingertip, or the palm under the base of the fingers. It hurts when pressed. The surrounding skin still has normal fingerprint lines.
Cause Common causes seen in the clinic
Hand tools Hammers, screwdrivers, pruning shears and wrenches, where the handle presses on the base of the fingers and the palm every day.
Pens and pencils People who write a lot get them on the side of the middle finger's last joint where the pen rests. It is usually a raised callus, but in some people it becomes a small corn.
Weightlifting and fitness equipment Barbells, dumbbells and pull-up bars thicken the palm under the base of the fingers and can produce corns within it.
Musical instruments Guitar strings, bass strings or a violin bow thicken the fingertips. Most of this is callus, which musicians want anyway.
Walking aids and racket sports Canes, crutches, wheelchairs, tennis rackets and badminton rackets press on the same spot on the palm every day.
Severity/urgency Low. Corns on the hands rarely break down into sores because they do not bear body weight. The main problems are pain when gripping and confusion with common warts on the hands, which are much more frequent, especially in children and teenagers.
When to see a doctor A bump with black dots, a rough cauliflower-like surface, spreading into several bumps, or appearing in someone who does not do heavy manual work, because these point to a wart rather than a corn. Any bump on the hand that grows quickly, changes colour or bleeds on its own should always be examined.
What causes corns? Five mechanisms that thicken the skin
Corns are not caused by germs, are not caught from other people and are not caused by dirt. Every case can be traced back to a mechanical force.
Tight, narrow or high-heeled shoes They squeeze the toes together and push the whole body weight onto the ball of the foot. Heels higher than 5 centimetres clearly increase pressure on the forefoot.
Loose shoes or going without socks The foot slides around in the shoe with every step, and the skin is rubbed repeatedly in the same place. Flip-flops and shoes without a heel strap also fit this category.
Foot deformities Hammer toes, bunions, flat feet, high arches, or a metatarsal bone that is longer than normal make weight fall unevenly and leave bony prominences pressing against the shoe.
Bony prominences and bone spurs Bone growing out near the toe joints or under the sole, and the fat pad under the sole thinning with age, bring the bone closer to the skin so it presses on the skin from inside.
Activities, occupation and gait Standing or walking for many hours a day, long-distance running, sports with sudden stops and starts, and an altered gait from pain in other joints. On the hands, it is gripping the same tool or equipment every day.
Who is at higher risk of corns than the general population?
Older adults The fat pad under the sole thins, the skin gets drier and toe deformities tend to accumulate. Corns and calluses are therefore among the most common foot problems at this age.
Women who regularly wear high heels or pointed shoes They are the group who most often get corns on the tops of the toes and under the forefoot during working age.
Runners, athletes and people who stand all day at work For example nurses, sales staff, chefs and soldiers.
People with foot deformities Hammer toes, bunions, flat feet or a past broken foot bone.
People with diabetes, peripheral neuropathy and peripheral vascular disease They do not get corns more easily than others, but corns in this group are far more dangerous.
People with rheumatoid arthritis or excess weight The ankles and toes are deformed and carry more load.
Tradespeople, musicians and users of walking aids For corns on the hands.
Is it a problem if you leave a corn alone?
A corn is not cancer, does not turn malignant and does not spread to other organs. In a healthy person, leaving it is therefore not seriously dangerous, but it will not go away by itself as long as the pressure is still there, and a sequence of problems often follows.
Increasing pain The core gets thicker and deeper every week it is pressed. What starts as pain only in tight shoes becomes pain with every step.
Unconsciously changed gait To avoid the painful spot, the body changes how it loads the foot, followed by pain in the ankle, knee, hip or lower back, and new calluses or corns at the new pressure points.
Inflamed bursa under the corn Tissue under a corn that has been pressed for a long time forms a fluid sac for cushioning. When it becomes inflamed it is swollen, red, warm and many times more painful than an ordinary corn.
Bleeding under the thick layer and breakdown into an ulcer A dark red or black spot under the corn is a sign that the pressure is high enough to injure the tissue beneath. If the thick layer cracks open, it becomes an open wound that can become infected.
Chronic ulcers in people with diabetes and numb feet This is the case where a corn really must not be left. Without pain, the person does not realise there is a problem. Thickened skin that keeps being pressed breaks down into an ulcer beneath the thick layer, invisible from the outside. Research in people with diabetic neuropathy has found that having a callus or corn raises the risk of an ulcer at that spot about 11-fold, and a deeply infected diabetic ulcer is one of the leading causes of toe or foot amputation.
In short, most people can leave a corn for a while if they are willing to put up with the pain, but people with numb feet, diabetes or poor leg circulation need to deal with it while the corn is still small.
How to treat a corn yourself the right way
Self-care works well in healthy people whose corn is not very large. Follow this order.
Find the pressure and remove it first. This is the most important step and the one most often skipped. Switch to wide, soft-soled, low-heeled shoes and wear socks every time. For the hands, pad the tool handles, wear gloves or change how you grip. If you skip this, everything else works only temporarily.
Soak in warm water for 5–10 minutes, then rub gently. After soaking, rub gently in one direction with a pumice stone or foot file. Do this every other day or 2–3 times a week. Stop immediately if the skin turns red or stings. Do not rub the skin too thin. Never cut it yourself with a razor, scissors or any blade.
Keratin-softening medicine. Salicylic acid liquid or gel at about 12–17 percent, applied only on the corn once a day after soaking. Protect the normal surrounding skin with petroleum jelly first, or use a 40 percent salicylic acid patch cut to fit the corn and changed every 1–2 days. The dead skin turns white and peels off layer by layer. Use it continuously for no more than 2 weeks, then reassess. Another option is 10–20 percent urea cream applied to the whole sole every night to soften the skin, and 30–40 percent applied only to very thick spots.
Reduce pressure with pads. Place a ring-shaped or doughnut-shaped pad so that the corn sits in the hollow, which spreads the force to the surrounding area. For corns between the toes, use silicone toe separators or lamb's wool so the toes do not touch. For corns under the sole, use an insole with cushioning behind the metatarsal heads.
Moisturise every day. Apply a thick cream after bathing while the skin is still damp. Soft skin builds thick keratin more slowly and responds better to treatment.
Do not do the following
Do not use salicylic acid or corn patches if you have diabetes, peripheral neuropathy, peripheral vascular disease, or feet that are cold, pale or numb, because the acid can burn deep without being felt and the resulting sore is very hard to heal.
Do not apply patches on broken, wounded or inflamed skin, or between wet toes, and do not apply them over the normal surrounding skin.
Do not cut or dig out the core yourself. You risk cutting into healthy tissue, infection, and a scar that hurts more than the original corn.
Do not use over-the-counter products on young children. Most hard bumps on a child's foot are warts, not corns.
How does a doctor treat a corn?
At a dermatologist visit, the first thing that happens is to confirm that it really is a corn by paring away a thin layer of the surface and examining it with a dermatoscope. A corn shows a single clear core and skin lines curving around the lump, while a wart shows scattered tiny bleeding dots and interrupted skin lines. The doctor then looks at the structure of the foot and the shoes worn, and in people with diabetes also checks foot sensation and the pulse on the top of the foot.
Paring or debridement of the thick layer and core is the main treatment and works quickly. The doctor uses a sterile blade to pare away dead keratin layer by layer down to the core. No local anaesthetic is needed, there is no bleeding and it does not hurt, because what is removed is dead skin cells. The pain goes away immediately, as soon as you walk out of the room, and paring thick callus in people with diabetes reduces the peak pressure at that spot by about a quarter. The limitation is that if the pressure is still there, the corn slowly re-forms within 4–8 weeks, so repeat paring is usually scheduled in cycles together with fixing the underlying cause.
Stronger keratin-softening medicine than you can buy yourself, with more precise instructions for use, for corns not yet ready for paring or for people who want to continue care at home.
Cryotherapy (freezing) has very limited use. Extreme cold is designed to destroy virus-infected cells in warts, but a corn has no virus to destroy, and freezing does not reduce the pressure that causes it. The result is often pain, blisters and darkened skin while the corn still comes back. Dermatologists therefore do not use freezing as a standard treatment for corns. If someone recommends freezing a corn, first ask whether it has been confirmed that it is not a wart.
Custom insoles and pressure-adjusting devices When a corn is caused by foot structure, the doctor may prescribe insoles with cushioning behind the metatarsal heads, a toe splint, or a referral to an orthotist to correct weight distribution.
Referral to an orthopaedic surgeon only for corns that keep returning to the same spot even after everything above has been done, and where a clear driver such as a bone spur or deformed toe is found.
Do you need surgery for a corn?
Most people do not. Almost all corns heal by removing the pressure, paring the thick layer and using keratin-softening medicine.
"Cutting out" a corn surgically is not a recommended treatment for two reasons. First, a corn has no root to cut out. Surgery that cuts that skin away leaves a scar on skin that has to bear weight, and a scar on the sole is often more painful and harder than the original corn. Second, if the bony prominence and the shoe still press on the same spot, a corn will re-form on that scar anyway.
Surgery has a real use in only one situation: when the driver is bone, and full non-surgical treatment for 3–6 months or more has still not stopped the corn from returning. Examples are a hammer toe with a stiff joint that cannot be straightened, a bone spur at a metatarsal head or toe joint, or a severe bunion. In these cases the orthopaedic surgeon operates to correct the bone that is pressing, not to cut out the corn. Once the pressure is gone, the corn slowly disappears on its own with the skin renewal cycle.
So if someone proposes cutting out a corn at the very first visit, before you have tried changing shoes, paring the thick layer or having the foot structure assessed, you should ask for a second opinion.
How many days does a corn take to heal?
The answer depends on whether the pressure can really be removed. The outer skin renews itself about every 4 weeks, so thickened skin needs at least one full cycle to become thinner.
After the doctor pares the thick layer The pain is gone the same day. The skin there becomes soft and smooth again within 1–2 weeks.
When the pressure is removed and you continue care at home A small, recent corn softens within 1–2 weeks and becomes smooth and normal in 2–6 weeks.
A corn that has been there for months or has a deep core May take 2–3 months and often needs 1–2 repeat parings along the way.
Using keratin-softening medicine yourself White peeling skin starts to appear within 3–5 days and the lump becomes clearly smaller within 1–2 weeks. If nothing has changed at all after 2 weeks, stop and see a doctor to confirm the diagnosis.
If the pressure is still there It will never heal permanently, whether you pare it, use medicine or even have surgery.
Why do corns keep coming back?
In almost every case this question has one answer: the underlying pressure has not been fixed. The most common causes are
Going back to the same shoes once the pain is gone, especially work shoes and high heels worn for many hours a day.
A foot structure that has not been corrected: bent toes, a bunion, flat feet or a bone spur still pressing on the skin from inside with every step.
Walking or running with the same gait, the same distance and the same hard surfaces.
A fat pad under the sole that has thinned with age, which cannot be reversed but can be compensated for with cushioned insoles.
Dry skin that is not kept moisturised, which makes the skin thicken faster than normal.
A randomised study in people with corns compared a 40 percent salicylic acid patch with paring by blade alone. At 3 months, about 1 in 3 in the patch group had cleared, compared with about 1 in 5 in the paring group, and when followed for 1 year, both groups had a high proportion of recurrence. The practical conclusion is that the method of removing the lump is not the deciding factor. Stopping the pressure is what decides whether it heals permanently.
Shoes, insoles and correcting the foot structure
Shoe-choosing rules that apply to every type of corn
Measure or try on shoes in the afternoon or evening, when the feet are at their fullest.
Leave about 1 centimetre, or the width of a thumb, between the longest toe and the front of the shoe.
The toe box should be wide and tall enough for every toe to move without touching the top or sides.
Heels no higher than 3–4 centimetres, with a strap or a heel counter so the foot does not slide forward.
The inner sole should be soft and thick enough, the upper material flexible, and socks seamless or with flat seams.
Insoles Ready-made ones with cushioning behind the metatarsal heads work well for corns under the forefoot in most people. Custom insoles moulded to the foot suit people with clear foot deformities or corns that have returned several times.
Correcting the structural drivers
Flat feet Insoles with arch support and foot muscle exercises, so weight does not fall onto the inner base of the toes.
Hammer toe Shoes with a tall toe box, a pad under the toe so the tip does not dig into the ground, and a toe splint if the joint can still be straightened. Surgery to correct the bone is considered only once the joint has become stiff.
Bunion Wide shoes, silicone pads over the bony prominence, toe separators, and corrective bone surgery only in people with significant pain and deformity.
Bone spur under the sole or at a toe joint A ring-shaped pad to lift pressure off the prominence. If that does not work, an orthopaedic surgeon can trim the bone that has grown out.
What should people with diabetes be especially careful about?
In people with diabetes, a corn is not a cosmetic matter or a nuisance. It is a warning sign that the spot has high pressure and is about to become an ulcer.
Do not use salicylic acid, corn patches or any corrosive products, and never cut, scrape or pick at it yourself under any circumstances.
Have a doctor or foot-care team pare the thick layer in cycles as scheduled. Correct paring is part of preventing diabetic ulcers.
Check your feet with your eyes every day, including between the toes and the soles using a mirror. Look for colour changes, redness, cracked skin, weeping, or black spots under thick skin.
Have foot sensation and pulses checked at least once a year. People found to have numb feet need to be checked more often, because they will not feel pain when a corn is turning into an ulcer.
Wear diabetic shoes or shoes your doctor recommends, and check inside the shoes before putting them on every time.
Signs that need a doctor within 24 hours: redness, warmth or swelling around the corn, weeping or pus, a smell, darkening skin colour or a fever, even if it does not hurt at all.
The same principles apply to people with peripheral neuropathy from other causes and people with narrowed leg arteries.
When should you see a dermatologist?
You are not sure whether it is a corn, a callus or a wart, especially if there are black dots, several lumps, or it is in a child.
It hurts so much that walking is difficult or you have to change the way you walk.
You have cared for it correctly for 2–3 weeks with no improvement, or it has come back in the same spot 2 or more times.
A corn between the toes that is macerated, has cracks or has a smell.
You see dark red or black colour or blood under the corn, or the surrounding skin is red, swollen or warm.
You have diabetes, numb feet, peripheral vascular disease or low immunity. See a doctor while the corn is still small, without waiting for it to hurt.
A bump on the hand or foot that grows quickly, changes colour, has an irregular shape or bleeds on its own.
Assessing hard bumps on the feet and hands, and choosing a treatment, must be done by a doctor after a physical examination. For other skin conditions of the feet, see Skin conditions article index
Key points
A corn is thickened skin with a hard core caused by repeated pressure on the same spot. It is not a germ, is not contagious and has no root.
Tell it from a wart by black dots, interrupted skin lines and pain on squeezing. Tell it from a callus by the sharp border and central core.
It can occur on the hands from tools, pens, barbells, musical instruments and walking aids, but it must be told apart from warts on the hands, which are more common.
Left alone in the general population, it just hurts more, but in people with diabetes and numb feet it raises the risk of an ulcer about 11-fold.
Treatment that works is removing the pressure + paring the thick layer + keratin-softening medicine. Freezing has almost no use, and surgery is used only to correct a driving bone in people whose corn keeps returning despite other treatment.
How many days to heal? The pain goes away immediately after paring, and the skin is smooth in 2–6 weeks if the pressure is really removed.
Frequently asked questions
How do you get rid of a corn?
Start by finding the pressure and removing it. Switch to wide, low-heeled, soft-soled shoes and wear socks every time, or pad the tool handle if it is on the hand. Then soak in warm water for 5–10 minutes, rub gently with a pumice stone every other day, apply salicylic acid only on the corn or urea cream every night, and use a ring-shaped pad to spread the force. If it is very painful or the lump is thick, the doctor will pare away the thick layer and core, which relieves the pain immediately without any anaesthetic injection. The corn becomes smooth and normal in 2–6 weeks once the pressure is really gone, but if you go back to the same shoes it will return to the same place within 1–2 months, however it was removed.
Is it a problem if you leave a corn alone?
In a healthy person a corn is not cancer and does not progress into another disease, but it will not go away by itself while it is still being pressed, and it usually hurts more every week until you change the way you walk, followed by knee or back pain, an inflamed bursa under the corn, or a breakdown into an infected ulcer. The cases where it truly cannot be left are people with diabetes, numb feet and poor leg circulation, because without pain a corn turns into an ulcer beneath the thick layer without being noticed. Thick skin on the feet in this group raises the risk of an ulcer about 11-fold, and a deeply infected diabetic ulcer is a leading cause of toe or foot amputation.
Do you need surgery for a corn?
Most people do not. Almost all corns heal by removing the pressure, having a doctor pare the thick layer, and using keratin-softening medicine. Surgically removing a corn is not the recommended method, because a corn has no root to cut out, and a scar on weight-bearing skin often hurts more than the original corn, and the corn still returns on that scar if the pressure is still there. Surgery has a real use only when the driver is bone, such as a hammer toe with a stiff joint, a bone spur or a severe bunion, and full non-surgical treatment for 3–6 months has still not stopped it returning. The orthopaedic surgeon then operates to correct the pressing bone, not to cut out the corn.
What medicines can treat a corn?
The medicines used are keratin-softening ones. The main one is salicylic acid: liquid or gel at about 12–17 percent applied only on the spot once a day, or a 40 percent patch cut to fit the corn and changed every 1–2 days, protecting the surrounding skin with petroleum jelly, used for no more than 2 weeks and then reassessed. The other group is urea cream, 10–20 percent applied to the whole sole every night and 30–40 percent applied only to very thick spots. There is no oral medicine for corns, and no antiseptic is needed unless there is an infected sore. None of these may be used by people with diabetes, numb feet or leg vascular disease, who should be treated by a doctor.
What causes corns on the fingers?
Corns on the fingers arise by the same mechanism as on the feet: repeated pressure or friction on the same spot over a finger bone. Common causes are the handles of hand tools such as hammers, screwdrivers and scissors, a pen resting against the side of the middle finger in people who write a lot, barbells and pull-up bars in people who exercise, guitar strings, and the handles of canes, badminton rackets or wheelchairs. They usually appear on the back of a finger joint, the side of a finger or the palm under the base of the fingers, and they hurt when pressed, while the fingerprint lines around them remain normal. Be careful, because most hard bumps on the hands are common warts, which have black dots, a rough surface and can spread. If you do not do heavy work with your hands or the bump has those features, have a doctor examine it before treating it yourself.
Can corn patches be used?
They can be used by healthy people who use them correctly. Most patches contain 40 percent salicylic acid. They must be cut to fit the size of the corn, must not cover normal skin and must be changed every 1–2 days. Soak and gently rub off the dead white skin before applying a new patch, and stop using them if the surrounding skin turns red or stings. Do not use them continuously for more than 2 weeks. Research has found patches work no differently from, or slightly better than, paring alone at 3 months, but recurrence is high if the pressure is not fixed. They must not be used by people with diabetes, numb feet, peripheral vascular disease, young children, on broken or inflamed skin, or on soft corns between wet toes, because the acid can burn deep enough to cause a sore without being noticed.
The information in this article is for general understanding and is not a diagnosis or individual treatment. Assessing hard bumps on the feet and hands, and choosing a treatment, should be done by a doctor.
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed September 7, 2026
Comments