Seborrheic Keratosis
A seborrheic keratosis is a common, harmless growth that looks stuck onto the skin, like a piece of wax or a small barnacle. They are not cancer and they do not become cancer. The reason to see a doctor is to be sure that is what you are looking at.
Key facts
Seborrheic Keratosis at a glance.
Typical signs
Waxy, stuck-on growths
Common locations
Back, chest, face
Expected course
Persist; more may appear
Treatment options
Usually none; optional removal
What is it?
Top things to know about Seborrheic Keratosis
- It is a benign growth. Surface skin cells form a waxy, warty or stuck-on growth.
- Color varies. It can be tan, brown, gray or almost black.
- It is not a precancer. These growths become more common with age.
- Uncertain lesions are tested. Tissue is examined before any destructive treatment if the appearance is unclear.
What it looks like
What Seborrheic Keratosis looks like
Seborrheic keratoses are common, harmless skin growths that appear with age. They often look waxy and stuck on, as if they could be peeled off. They range from light tan to black and can be flat or raised, smooth or rough. They usually appear on the chest, back, face and scalp, and many people have several. They don't turn into cancer, but a new or changing dark spot should be checked.
Seborrheic keratoses have a few common variants.
Classic seborrheic keratosis
Raised, waxy, stuck-on growth.
Stucco keratosis
Small white-gray bumps on the legs.
Dermatosis papulosa nigra
Small dark bumps on the face.
Where it shows up
Location varies
These growths occur at many skin sites and do not follow one fixed distribution.
On different skin tones
Seborrheic Keratosis on different skin tones
Seborrheic keratoses appear on all skin tones. On lighter skin, they look tan to brown. On brown and Black skin, a variant called dermatosis papulosa nigra is common, appearing as many small dark bumps on the cheeks and forehead, often starting in early adulthood.
What happens in Seborrheic Keratosis?
A benign overgrowth of surface skin cells creates a localized plaque. Keratin and sometimes pigment collect in the growth, giving it a waxy, rough or stuck-on appearance.
- A stuck-on plaque appears: The surface can look waxy or rough.
- Keratin collects in the growth: Tiny keratin-filled spaces may form.
- Surface cells grow locally: A benign epidermal growth develops.
Causes and triggers
What causes Seborrheic Keratosis
Causes
Why it happens
Seborrheic keratoses are harmless growths of skin cells that become more common with age.
They often run in families.
Risk factors
Raise the odds
- Age over 50
- Family history
- Sun exposure
Triggers
Bring it on or make it worse
- Aging (Well established)
- Sun exposure (Possible)
When it usually starts
When it usually starts
Seborrheic Keratosis
Usually appears in adult life and becomes increasingly common with age.
Daily care
Daily care for Seborrheic Keratosis
Watch for change, not for existence
Growing, darkening, bleeding or newly itchy.
Then leave it alone
Avoid picking or rubbing a growth confirmed as benign.
Curettage or shave removal
Precise, and it yields tissue to examine.
Daily sunscreen on treated areas
Keeps the mark from deepening.
Discuss how age affects monitoring and recovery
The biggest driver of how many you get.
Tell the clinician about your family history
Why one person has one growth and another fifty.
Avoid: Sun exposure
Adds to the count, and darkens marks after removal.
Avoid: Assuming a dark growth is benign
Melanoma is mistaken for one.
Avoid: Picking or peeling one off
They bleed, inflame, and mark.
Avoid: Friction from clothing
Straps, waistbands and belts irritate growths.
Avoid: Shaving over them
The usual cause of sudden bleeding.
Avoid: Home freezing kits and acid pens
They scar something nobody examined.
Avoid: A sudden crop of many new ones
Many at once should be assessed.
Avoid: Removal without a diagnosis
Destroyed tissue cannot be analyzed.
Avoid: Home freezing and acid kits
Do not freeze or burn unexamined growths at home; tissue may need examination.
Treatments
Treatments for Seborrheic Keratosis
Urea
A strong urea cream can soften and flatten the rough white growths that scatter over the lower legs, called stucco keratoses, if the roughness is what bothers you. It smooths the surface rather than removing the growth, and it has to be used continuously. It does nothing for thick, dark, stuck-on growths elsewhere.
Salicylic Acid
Wart treatments are often tried on these because the surface looks similar. Salicylic acid can thin the rough top layer, but it does not clear the growth, and it irritates the normal skin around it. The bigger problem is that it is usually being used on something nobody has examined.
Petrolatum
This is aftercare, not treatment. A thin layer of plain petroleum jelly over a treated spot keeps the scab soft and gives the neatest healing, under a small dressing rather than an adhesive strip. It does nothing to a growth that is still there.
Zinc Oxide
Daily mineral sunscreen over a spot that has just been treated stops the temporary mark from darkening and helps it fade faster, which matters most on the face, chest and hands. It will not remove a growth or stop new ones forming. Sun is only one of several things that drive these, and age and family history matter more.
Eskata
A high-strength peroxide solution applied in clinic was approved for raised growths on the face and body. It cleared some growths, often needed repeat visits, and commonly caused stinging, crusting and pigment change. It was withdrawn from sale in the United States, so in practice removal is done by hand rather than with a liquid.
Shave Removal
The growth is numbed and shaved off level with the skin in a few seconds. It is the method of choice when there is any question about what a growth is, because it produces tissue that can be sent to the laboratory. It leaves a flat mark that fades over months, and it does not stop new growths appearing elsewhere.
Electrodesiccation and Curettage
The growth is scraped off with a small curette and the base sealed with a fine electric tip. It is controlled and shallow, which is why it is often preferred for small facial growths and for the dark facial growths common on deeper skin tones. Scraping first still gives tissue that can be examined if there is doubt.
Cryotherapy
A few seconds of liquid nitrogen makes flatter growths blister and lift off over a week or two, and it is the quickest way to treat several at once. It destroys the growth, so nothing can be examined afterward, which is why it is not used on anything with a question attached. It is used cautiously on the face and on deeper skin tones, because the pigment cells are sensitive to cold and it can leave a pale spot.
Fractional CO2 Laser
An ablative laser can vaporise a growth precisely and is sometimes used when several need treating on the face. Like freezing, it destroys the tissue, so it is only for growths already confirmed as harmless. It is the most expensive of the options and it is not better than a curette for a single growth.
Skin Biopsy
When a growth is changing, bleeding on its own, or simply looks unlike your others, part or all of it is taken after numbing and examined under a microscope. It is the only way to be certain, and the threshold for doing it is deliberately low, because the cost of a small biopsy is trivial next to missing a melanoma. An irritated growth is one of the commonest reasons a benign growth ends up being sampled.
Outlook
What to expect with Seborrheic Keratosis
Seborrheic keratoses appear slowly, change slowly, then stay. Two departures deserve attention: one growth that starts changing - growing, darkening, bleeding on its own, or itching persistently - and a sudden crop of many new ones over weeks to months.
- 1
Starting · Year 0
A flat, light tan patch appears, easily mistaken for a large freckle or an age spot.
- 2
Thickening · Years 1 to 5
The patch darkens and thickens, the edge sharpens, and the surface turns rough or waxy.
- 3
Settled · Years onward
It may darken slowly over years. It does not become cancerous and needs no monitoring beyond noticing change. More appear in the same areas, which is expected.
- 4
Irritation · Any time
A growth caught by clothing, a strap or a waistband can turn red, swollen, itchy, crusted or sore, and can bleed. That is an irritated seborrheic keratosis. It settles, but it looks alarming and often prompts removal or a sample.
- 5
After removal · One to three weeks
A treated spot scabs over one to three weeks, often leaving a flat mark darker or paler than nearby skin. Dark marks fade over months. Pale marks may be permanent.
Complications
Complications to know about
Catching on clothing makes it flare
A growth caught by clothing, a strap or a waistband can turn red, swollen, itchy, crusted or sore, and can bleed. That is an irritated seborrheic keratosis. It settles, but it looks alarming and often prompts removal or a sample.
When to get help
When to get help
When to seek care
Have a new, changing, bleeding or uncertain growth assessed; skin cancer can sometimes resemble a harmless stuck-on growth.
Lookalikes
What else could it be?
Melanoma
Seborrheic keratoses often resemble other growths you already have. A dark spot with changing shape, uneven colors or an unusual edge needs checking for melanoma.
Sun Spots
Sun spots remain flat and smooth. Seborrheic keratoses often become thicker, with a dry or waxy surface you can feel.
Warts
Warts may have tiny dark dots and can spread. Seborrheic keratoses often look brown and waxy and are not contagious.
Questions
Questions you might be asking.
Could this be melanoma?
It could be, which is why it should be looked at rather than diagnosed at home. Melanoma is sometimes mistaken for a seborrheic keratosis, and a dermatoscope resolves most of these in seconds. The concerning features are change in size, shape or color, bleeding without being knocked, an irregular edge, and a growth unlike your others. Book rather than watch.
Why am I suddenly getting so many?
Age and family history account for nearly all of it. They accumulate steadily from the forties onward, and someone whose parents had many will develop many. A genuinely sudden crop over weeks to months, especially with itching, is different and worth examining.
Does removing one stop more from appearing?
No. Removal deals with that growth, not the age and inherited tendency behind it, so new ones can keep appearing elsewhere. That is expected, not a failed removal.
Will removal leave a mark?
Often, at least for a while. A flat spot darker or paler than nearby skin is common, and dark marks usually fade over months. Pale marks can be permanent and are more noticeable on deeper skin tones, so ask about the method and do a test spot before treating a large area. Daily sunscreen on the treated spot makes a real difference.
Mine got red and itchy and started bleeding. What happened?
Most likely it caught on clothing, a strap or a razor and became an irritated seborrheic keratosis. They look far worse than they are and they settle. Still have it looked at - an irritated growth is one of the harder ones to be sure about by appearance, and a growth that bled with nothing catching it is a different question.
Can I have them all removed?
As many as you and your doctor think sensible, usually in sessions rather than all at once. It is normally considered cosmetic, so ask about cost first. On the face, and particularly on deeper skin tones, start with a small test area and see how it heals.
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