Seborrhoeic Keratoses
Harmless, warty or waxy spots that look stuck on to the skin, from pale to almost black. Extremely common after 50, often many at once. They can’t turn into cancer and aren’t contagious, so treatment is optional.
What they look like. Flat to raised, a few millimetres to a few centimetres across, with a rough, crumbly or waxy surface, on the chest, back, face, scalp or under the breasts. They can itch, catch on clothing or bleed when knocked. The cause isn’t known; they’re not viral warts and nothing to do with hygiene or diet. Many people inherit a tendency to get lots.
Diagnosis. Usually obvious to a doctor with a dermatoscope. Because a dark one can look like a melanoma, any spot that’s different from your others, changing fast or uncertain gets checked or removed for testing. On brown and black skin, many small dark bumps on the cheeks and around the eyes are often a related harmless condition called dermatosis papulosa nigra, which tends to run in families.
The seb K ladder
Most need nothing at all. Remove one if it’s uncertain, sore or catching, or if it bothers you and you’re happy to pay.
- Step 1 · Self-careLeave them aloneMoisturiser helps itchy ones. Avoid picking.
- Works
- They don’t go away on their own, but they’re harmless
- Cost
- Free
- How long
- Lifelong
- Watch for
- Any spot that looks different from the rest (the “ugly duckling”), or changes quickly: get it checked.
Barnacles of wisdom. Unglamorous, but harmless.
- Step 2 · GPA check if unsureA dermatoscope can usually tell a seb K from a melanoma or skin cancer.
- Works
- Usually confirms it in one look; uncertain spots are removed and tested
- Cost
- Often bulk-billed or about $40–100 out of pocket
- How long
- One visit
- Watch for
- Mention any spot that’s new, changing or bleeding.
Ninety-nine look the same. You’re hunting for the hundredth.
- Step 3 · ProcedureFreezing (liquid nitrogen)Quick spray to thin, flat ones. They blister, crust and fall off over a couple of weeks.
- Works
- No good trials comparing methods; usually removes thin ones, but they can regrow and new ones keep appearing
- Cost
- Often a private fee when it’s cosmetic: about $50–150
- How long
- One or two sessions
- Watch for
- Pale or dark marks, more noticeable on brown and black skin.
Cold, quick and mildly undignified.
- Step 4 · ProcedureScraping or shaving off (curettage, shave)Under local anaesthetic, for thick or irritated ones, or when a lab check is wanted.
- Works
- Removes the spot and gives tissue to test
- Cost
- GP: about $80–250 out of pocket; Medicare may cover it if there’s a medical reason
- How long
- One procedure; heals in 1–3 weeks
- Watch for
- Small scar or colour change. Raised scars are more common on darker skin.
The thick ones come off like a scab with a mortgage.
- Step 5 · SpecialistLaser or cautery for many small spotsUsually for dermatosis papulosa nigra or lots of small lesions on the face.
- Works
- Small studies only; can work well in experienced hands
- Cost
- Private cosmetic fees, often hundreds of dollars
- How long
- One to several sessions
- Watch for
- Ask about the risk of pigment change on your skin type before starting.
Pick someone who treats your skin tone a lot, not just sometimes.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Over-the-counter freeze kits, pens and removal creamsNo good evidence, and DIY risks burns, scars and missing a melanoma that looked like a seb K.
- Apple cider vinegar, tea tree oil or garlicNo trials. Can burn the skin around the spot.
- Diet or supplements to stop new onesNothing in diet or lifestyle has been shown to prevent them.
What you can do
- Get to know your spots so you notice one that’s different.
- Moisturise itchy ones and wear soft fabrics where they rub.
- Use sun protection anyway: the same skin can still get skin cancer.
See your GP if
- One spot looks different from the others, or is changing quickly
- A spot bleeds without being knocked, or doesn’t heal
- A spot is sore, inflamed or keeps catching
- Lots of new spots appear suddenly over a few months (rare, but worth a check)
Not sure if it’s a seb K or a mole? Don’t treat it yourself. Melanoma can look similar, and DIY removal destroys the tissue a lab would need.
Common questions
Can seborrhoeic keratoses turn into cancer?
No. They’re harmless. The only worry is mistaking a melanoma for one, so changing or unusual spots should be checked.
Are they contagious?
No. They’re not viral warts and don’t spread to other people.
Why do I keep getting more?
They become more common with age and often run in families. New ones are normal.
Does Medicare cover removal?
Usually only when there’s a medical reason, such as an uncertain diagnosis, bleeding or inflammation. Cosmetic removal is usually private.
Helpful resources
- Primary Care Dermatology Society: Seborrhoeic keratosesClear patient leaflet on what they are and when they need a check. Free, UK.
- Melanoma Institute AustraliaWhy checking the odd one out matters. Free, Australia.
Evidence and more information
- Primary Care Dermatology Society: Seborrhoeic keratoses
- British Association of Dermatologists: Seborrhoeic keratosis leaflet
- NHS: Skin tags (removal risks on darker skin)
maladywise.com/seborrhoeic-keratosis/