Condition

Seborrheic Keratosis

A seborrheic keratosis is a harmless skin growth that looks stuck on the surface, like a blob of wax or a scab that will not come off. They are extremely common after 40 and are not cancer.
At a Glance

A seborrheic keratosis is a harmless overgrowth of the top layer of skin. The tell is that it looks stuck on rather than growing out of the skin, with a waxy, crumbly, slightly rough surface. They are not cancer and they do not turn into cancer, so removing one is a cosmetic choice rather than a medical need. The honest caveat: a growth that is new, changing, bleeding or itchy — especially one that looks unlike your others — should be shown to someone, because a melanoma can look very like one.

Key Facts

How CommonExtremely common. Most people over 50 have at least one, and many have dozens.
Who Gets ItAdults, usually from the late thirties onward. They increase with age and run strongly in families.
Chronic or CurablePermanent unless removed. They do not go away on their own, and new ones keep appearing with age.
Rx RequiredNo. There is no prescription cream that removes them. Removal is a procedure.
ContagiousNo.
CostRemoval is usually treated as cosmetic and paid out of pocket. It is normally covered when a growth is removed because it is irritated, bleeding, or being checked for cancer.

Symptoms

−

Seborrheic keratoses do not hurt and cause no symptoms. They matter because of how they look, and because of what they get mistaken for.

What it looks and feels like

A stuck-on look — the most useful feature by far. It sits on the skin like a blob of candle wax or a scab, with a defined edge, rather than blending into the skin around it.
A waxy, crumbly or warty surface — often slightly greasy to the touch. Some are smooth and flat, especially early on.
Colour from pale tan to dark brown or black — a very dark one is often what sends people looking for answers.
Tiny plugged openings on the surface — small dark or white dots, sometimes visible without magnification.
A few millimetres to a couple of centimetres — usually raised enough to catch a fingernail on.
Itch or soreness if rubbed — one under a bra strap or waistband can become crusty and bleed a little. That is friction, not danger.

Where it shows up

  • The chest, back and shoulders — the most common sites, often dozens at once.
  • The face, temples and hairline.
  • Under the breasts, in skin folds and around the waistband, where they get irritated.
  • The neck and the sides of the trunk.
  • Not on the palms, soles or inside the mouth.

How it looks on different skin tones

On brown and Black skin, these often appear as many small, dark, slightly raised spots on the cheeks, temples and neck, sometimes starting as early as the twenties. That pattern has its own name — dermatosis papulosa nigra — and it is the same kind of harmless growth. It is strongly inherited. It also matters for treatment: this skin marks more easily, so removal needs a gentle technique and a light hand.

Light
Medium
Brown
Deep

Some of these look very like more serious things. See Lookalikes near the bottom of this page.

Causes & Risk Factors

−

Seborrheic keratoses come from the skin's own outer cells multiplying and piling up in one spot. The cells are ordinary skin cells behaving in a benign way. They are not a virus, they are not caught from anyone, and despite the name they have nothing to do with hygiene or with being unclean.

Age and genetics do most of the work. They start appearing in the late thirties and keep coming, and if your parents had a lot of them you probably will too. Most carry a change in a gene called FGFR3, which switches on this harmless overgrowth. Sun exposure appears to add to the number on exposed skin, but they also turn up on skin that never sees the sun, so sun is a contributor rather than the cause. Hormonal shifts, including pregnancy, can bring on a crop of new ones. None of this makes them dangerous — a seborrheic keratosis does not become a skin cancer.

What Hurts and What Helps

−

What Makes It Worse

  • Friction. A growth under a bra strap, waistband, collar or watch gets rubbed, becomes crusted and sore, and can bleed. This is the usual reason one starts to bother someone.
  • Catching them with a towel, a razor or a fingernail. They sit proud of the skin and are easy to snag.
  • Age. New ones keep appearing over the years, and nothing prevents that.
  • Picking or scratching them off. They usually grow back, and picking risks infection and a lasting mark.
  • Sun exposure, at least on exposed skin, where they tend to be more numerous.

Daily Habits That Help

  • Reducing friction. Changing what rubs against them — a different strap, looser clothing, a barrier ointment over one that catches — settles most irritated ones.
  • Accepting that nothing you put on your skin removes them. No cream, acid, oil or supplement clears a seborrheic keratosis. Products that soften the surface can make one look flatter for a while, and that is all they do.
  • Leaving them alone. They are harmless, and untreated they do nothing at all.
+2 more
  • Removal, if the look or the rubbing bothers you. A few seconds of freezing, or a shave with a blade under local anaesthetic, clears one properly. It is quick, it works, and wanting it is legitimate.
  • Knowing which spots are yours. The most useful habit with these is familiarity, because the growth that suddenly looks different from all the others is the one worth checking.

Try at Home

−

Be clear about what these do: nothing you can buy removes a seborrheic keratosis. They soften a rough surface or reduce the rubbing that makes one sore, and that is the whole of it.

Always
The most useful thing for a growth that is catching on a strap or waistband. A dab of ointment over it reduces the rubbing that makes one crusted and sore. It does not shrink or remove the growth.
Always
Sun exposure adds to the number of these on exposed skin, though it does not fully explain them. The stronger reason to use it: sunscreen protects against the growths that are not harmless, which is the actual worry when a new spot appears.
Limited evidence
Softens a rough, scaly surface so a growth feels smoother and looks slightly flatter. It does not remove it, and if you stop using it the surface builds back up.
Limited evidence
Same idea as ammonium lactate — it breaks down the thick surface layer so a growth is less rough to the touch. Useful if the texture bothers you, useless if you want it gone.
Limited evidence
Thins the crusty surface of a growth over weeks of daily use. Some people find a thin, flat one becomes less noticeable. A thick one will not budge, and the acid irritates the normal skin around it.
Limited evidence
These are designed for warts and are hard to control. On a seborrheic keratosis they often leave a permanent pale patch, and worse, they destroy a growth nobody has confirmed is harmless. Not worth it.

When to See a Dermatologist

−

Most seborrheic keratoses never need a visit. Go if:

  • One is new, growing, changing colour, or looks different from your others. This is the reason that matters most.
  • One bleeds, itches persistently, or will not heal.
  • One is sore or catching on clothing and you want it gone.
  • You have a lot of them and want them removed for appearance.
  • Many appear suddenly over a short time. This is rare and worth mentioning, though it is far more often just age.
  • You cannot tell a growth apart from a mole and it worries you.

What the visit gets you: a dermatoscope over the spot, which settles most of these in seconds, a biopsy if it does not, and removal in the same appointment if you want it.

What Happens at the Dermatologist?+

Seborrheic keratosis is usually recognised on sight, but this is one condition where a test genuinely changes things, because the thing it can be confused with is melanoma.

Dermoscopy is the main one. A dermatoscope is a handheld magnifier with a light that shows structures below the surface. Seborrheic keratoses have a distinctive look under it: small round plugged openings, whitish cysts within the growth, and a sharply defined, moth-eaten edge. This is what separates them from melanoma most of the time. It takes seconds, it does not touch the skin, and it costs nothing extra.

A skin biopsy settles it when dermoscopy does not. The area is numbed and a sample taken, usually by shaving the growth off flush with the skin, then sent to a laboratory. If a growth looks even slightly off, this is the right answer, because it removes the growth and answers the question at the same time.

There is no blood test and no scan for this. If a spot is called fine without either a dermatoscope or a sample, it is fair to ask which one was done.

In-Office Treatments

−

This is the only category that actually removes them. All of these work, they take minutes, and the choice mostly comes down to how thick the growth is and whether anyone wants it looked at under a microscope.

Strong evidence
A few seconds of liquid nitrogen, and the growth crusts and drops off over one to three weeks. Fast and effective for thinner ones. It often leaves a pale mark, which matters more on brown and Black skin.
Strong evidence
The growth is numbed and shaved off flush with the skin in one go. The advantage over freezing is that it is gone immediately and the tissue can be sent to a lab — which is the right choice if there is any doubt about what it is.
Strong evidence
The growth is scraped off with a small scoop after numbing, and the base sealed with a fine electric tip. Good for thick, raised growths, and it stops the bleeding as it goes.
Strong evidence
Not a treatment, but the right answer when a growth does not look quite right. It removes the growth and tells you definitively whether it was a harmless keratosis or something that needs treating.
Moderate evidence
A precise laser that vaporises the growth layer by layer. It gives good cosmetic results on the face and is useful when there are many small ones, but it costs more than freezing or shaving.
Moderate evidence
Another laser option, often used when there are a lot to clear at once. It works, but it carries slightly more risk of a pale mark or a scar than erbium, and again nothing is left to send to a lab.

What to Expect

−
Step 1
If you leave it alone

Nothing happens. It stays, it may thicken slowly over years, and more will appear elsewhere. It will not turn into anything.

Step 2
After freezing

The growth darkens and crusts over a few days, then falls off within one to three weeks. Sometimes a second treatment is needed. A pale mark afterwards is common and can be permanent.

Step 3
After shave removal or curettage

A small raw patch heals over one to two weeks under petroleum jelly. Most people are left with a flat mark that fades. This method has the advantage that the tissue can be sent to a lab.

Step 4
Marks left behind

A lighter or darker patch where the growth was is normal, and on brown and Black skin the darker mark can take many months to fade. Worth knowing before agreeing to have twenty removed at once.

Step 5
The long view

Removing one does not stop new ones. Most people who get these get more with each decade, and the reason to remove any given one is simply that it bothers you now.

Complications

−

Seborrheic keratoses are harmless. They do not spread, they do not become cancer, and untreated they cause nothing.

A few practical problems do come up.

  • Irritation and bleeding. One sitting under a strap or waistband gets rubbed raw and crusts over. Annoying rather than dangerous, and a fair reason to have it removed.
  • Infection. A growth picked or scratched open can become infected. Spreading redness, pus and tenderness need an antibiotic.
  • A missed melanoma. This is the real risk, and it runs the other way: a melanoma assumed to be a harmless keratosis and left alone. It is why a new, changing or odd-looking growth gets checked rather than dismissed.
  • Marks after removal. A pale or dark patch where the growth was, more noticeable and longer lasting on brown and Black skin. Small scars are possible if removal went deep.
  • Regrowth. A growth removed only at the surface can come back in the same spot.

A sudden crop of many new seborrheic keratoses with itching has been linked to internal cancer in old case reports. It is very rare, most people noticing more growths are simply getting older, and it is a reason to mention it rather than to worry about it.

Lookalikes

−

This is the section that matters most on this page. The stuck-on look is the tell, but several things share it.

  • Melanoma. The one that counts. A melanoma can be dark, raised and irregular in exactly the way a seborrheic keratosis can. The warning signs are a growth that is new, changing, has an uneven border or several colours in it, or simply looks unlike all your others. A dermatoscope settles most of these in seconds, and anything doubtful gets biopsied.
  • Pigmented basal cell carcinoma. A pearly, slightly translucent bump with fine blood vessels over it, which may bleed and scab repeatedly. It grows slowly and does not heal.
  • Actinic keratosis. A rough, sandpapery patch on sun-exposed skin, easier to feel than to see, and flat rather than stuck on. These can become skin cancer, which is why they are treated.
  • Wart. Rough and grainy with tiny black dots, usually on hands and feet, and caused by a virus. Seborrheic keratoses are not infectious.
  • Mole. Smoother and more evenly coloured, and it grows out of the skin rather than sitting on it. Moles usually appear before 40, seborrheic keratoses after.
  • Skin tag. Soft and floppy on a narrow stalk. A seborrheic keratosis is flat against the skin on a broad base, though small ones on the neck can look tag-like.
  • Solar lentigo (age spot). Flat, tan and completely smooth. A seborrheic keratosis often starts as one of these and thickens over years.
FAQ+
Is a seborrheic keratosis cancer?No. It is a benign growth of ordinary skin cells, and it does not turn into skin cancer. The reason they are taken seriously is that a melanoma can look like one, not that they become one.
How can I tell it apart from a melanoma?The most useful home clue is that a seborrheic keratosis looks stuck on, has a waxy or crumbly surface, and looks like your other ones. A growth that is new, changing, multi-coloured, irregularly edged, or the odd one out deserves a professional look. This is not something to settle by staring at photos online.
Why do I suddenly have so many?Age, mostly, plus genetics. They accumulate steadily from the late thirties onward. A large number appearing over a few weeks with itching is rare and worth mentioning to a doctor, but for almost everyone this is simply time passing.
Will they go away on their own?No. They are permanent unless removed.
Can I remove one at home?No. Picking or shaving one off yourself risks bleeding, infection and a scar, and it destroys the tissue that would tell you if the growth was not what you assumed. Home freezing kits are not designed for these and often leave a pale mark.
Is there a cream that gets rid of them?No. Urea, ammonium lactate and acids can soften a rough surface and make one look flatter, but nothing you apply removes the growth.
Does removing one make more grow?No. New ones appear because of age and genetics, not because of anything you did to the old ones.
Does insurance cover removal?Usually not, if the reason is appearance. It is normally covered when a growth is irritated, bleeding, or being removed because the diagnosis is not certain. Ask before you book.
Does it hurt to have one removed?Freezing stings for a few seconds. Shave removal is done after a numbing injection, so you feel pressure rather than pain.
Are they caused by sun?Partly. They are more numerous on sun-exposed skin, but they appear on covered skin too, so sun is a contributor rather than the cause.
Are they contagious?No. They are not caused by a virus and cannot spread to anyone else, or to other parts of your own body.
What are the small dark bumps on my cheeks and neck?If you have brown or Black skin, these are most likely dermatosis papulosa nigra, which is a form of seborrheic keratosis. They are harmless, they run in families, and they can be removed with a gentle technique if you want them gone.