Seborrheic Keratosis Diagnosis: Is It Harmless and What Happens Next?

A seborrheic keratosis diagnosis means a clinician has identified a common, non-cancerous skin growth. The American Academy of Dermatology (AAD) describes these growths as harmless despite their appearance, and Cleveland Clinic states that they are not precancerous. Most people do not need treatment.

Seborrheic keratoses (the plural) usually appear in middle age or later, and many people have several. MedlinePlus notes that the cause is unknown and that they tend to run in families. They are not contagious, so they do not spread by touch.

This guide is for adults who have been told a skin growth is a seborrheic keratosis, after an examination or on a biopsy report. It explains the general picture and helps you plan questions. It cannot confirm what any particular spot is.

A diagnosis covers the growth that was examined, not every mark on your skin, and not changes that happen later. Cleveland Clinic advises seeing a provider in the situations below. MedlinePlus adds that a growth that appears on its own, has ragged borders or has irregular colour needs an examination for skin cancer.

• A new growth you cannot identify.
• A growth that itches, becomes irritated or bleeds.
• A change in an existing growth.
• Many new growths appearing suddenly over a short period.
• A mole that changes size, shape or colour, or is swollen, sore, bleeding, itchy or crusty, which the NHS lists as possible signs of melanoma.
• A growth or area of skin that hurts, itches, bleeds, crusts or scabs for more than 4 weeks, which the NHS advises getting checked.

The AAD describes some growths as having a warty surface and others as looking like dabs of brown candle wax on the skin. They range from white to black, though most are tan or brown. MedlinePlus describes them as slightly raised, rough or waxy, often round or oval, and sometimes appearing in groups.

They can appear almost anywhere except the palms and soles, most often on the chest, back, head or neck. They are usually painless, but they can catch on clothing or jewellery and become irritated. In people with darker skin, Cleveland Clinic notes that a related form called dermatosis papulosa nigra is more common.

Cleveland Clinic states that seborrheic keratoses are not precancerous, are not considered a risk factor for skin cancer and do not turn into melanoma. The concern is that they can look like other growths that are cancer, so a new or unusual growth should be diagnosed by a clinician rather than assumed to be harmless.

Cleveland Clinic contrasts them with melanoma. Seborrheic keratoses often occur in groups, have a textured surface and well-defined borders, are fairly even in colour and shape, and change slowly. Melanoma is often a single spot, may be smooth, with ragged or blurry borders and several colours, and can change quickly. These are general patterns, not a self-test.

They also differ from actinic keratoses, which are sun-damage patches that can occasionally become skin cancer. The two can look alike, which is another reason the diagnosis is made by a clinician.

The AAD says a dermatologist can usually recognise a seborrheic keratosis by looking at it. Cleveland Clinic adds that a dermatoscope, a handheld lighted magnifier, may be used when the clinician is unsure. If a growth looks like it could be skin cancer, the AAD explains that it is usually shaved or scraped off and examined under a microscope, because this is the only way to tell for sure.

A biopsy does not mean the clinician thought cancer was likely. It is a way to rule it out. If your report confirms a seborrheic keratosis, ask whether the whole growth was removed and whether any follow-up is needed. Keep the report with the date and body site so later changes can be compared.

Usually not. The AAD says removal may be considered if a growth looks like skin cancer, catches on clothing or jewellery, becomes easily irritated, or bothers you because of how it looks.

Options a dermatologist may use include freezing with liquid nitrogen, shaving or scraping (preferred when a sample is needed for testing), burning with an electric current followed by scraping, and laser treatment. The AAD notes that treated skin may look lighter for a time, sometimes permanently. A removed growth usually does not return, but new ones can appear elsewhere. Avoid trying to remove a growth yourself.

Bring a list of any other spots you want checked at the same visit.

• Was this diagnosed by examination, dermoscopy or biopsy?
• If a biopsy was done, was the whole growth removed, and does the report need any further action?
• Are any of my other spots ones you would like to watch or recheck?
• What changes should make me book an earlier appointment?
• Is removal worth considering for a growth that keeps getting irritated, and what are the trade-offs?
• Should I have regular skin checks because of my age, skin type or history?

Checking your skin from time to time helps you notice something new. Use a mirror or ask someone to check your back and scalp. Clear photos taken in the same light make it easier to show a clinician whether a spot has changed. Note the date, the body site and what changed, such as size, colour, bleeding or itching. Photos and notes support a conversation with a clinician; they cannot show whether a spot is harmless, so a change still needs an in-person check.

On SameCase, patients and verified doctors share de-identified cases. Reading how others with a seborrheic keratosis diagnosis described their growths, biopsy results and follow-up can help you prepare clearer questions. Other people's cases cannot tell you what your own spot is, and they are not a substitute for an examination. Take any change to a clinician who can see your skin.