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Seborrheic keratosis

See also in: External and Internal Eye,Anogenital,Hair and Scalp
Contributors: Susan Burgin MD, Belinda Tan MD, PhD, Sarah Hocker DO, Callyn Iwuala BA, Oyetewa Oyerinde MD, Noah Craft MD, PhD
Other Resources UpToDate PubMed


Seborrheic keratoses (SKs) are extremely common benign neoplasms of the epidermis that typically appear on the chest and the back. There can be few or hundreds of these raised, "stuck-on"-appearing papules and plaques with well-defined borders. The etiology is unknown, although there is a familial trait for the development of multiple SKs with an autosomal dominant mode of inheritance. SKs tend to increase in incidence and number with increasing age. They may start out as a flat wrinkled plaque with a "postage stamp" appearance (flat seborrheic keratosis). SKs are asymptomatic, but when irritated or traumatized, they may become pruritic or painful with associated redness or bleeding.  

A lichenoid keratosis is an inflamed seborrheic keratosis that presents as a pink shiny papule or plaque with an appearance that resembles that of a nodular or cystic basal cell cancer.

Dermatosis papulosa nigra is a term given to the papular seborrheic keratoses (most often seen as dark brown 1-3 mm papules) on the face of individuals with darker skin colors.

Relatively rapid onset of numerous SKs may be a cutaneous sign of internal malignancy. Multiple eruptive SKs in association with a visceral cancer is referred to as the sign of Leser-Trélat. The most common associated malignancy is adenocarcinoma of the gastrointestinal tract.


L82.1 – Other seborrheic keratosis

25499005 – Seborrheic keratosis

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Last Reviewed:01/30/2017
Last Updated:01/24/2022
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Patient Information for Seborrheic keratosis
Contributors: Medical staff writer


Seborrheic keratoses are common noncancerous (benign) growths of unknown cause seen in adults due to a thickening of an area of the top skin layer. Seborrheic keratoses may appear as if they are stuck on to the skin. They have distinct borders, and they may appear as papules (small, solid bumps) or plaques (solid, raised patches that are bigger than a thumbnail). They may be the same color as your skin, or they may be pink, light brown, darker brown, or very dark brown, or sometimes may appear black.

Who’s At Risk

Seborrheic keratoses can occur any time after puberty, and almost everyone older than 50 has one or more of these skin growths. They may increase in number with age. Members of the same family can have an inherited tendency to grow multiple seborrheic keratoses. Men and women are equally as likely to develop them. People with darker skin colors tend to develop seborrheic keratoses less frequently than those with lighter skin colors.

Signs & Symptoms

Seborrheic keratoses can occur anywhere on the body, except for the palms, soles, and mucous membranes (areas such as in the mouth or anus). They most commonly occur on the chest and back. Seborrheic keratoses do not go away on their own, and they do not become cancerous.

They usually start as light brown or skin-colored, slightly raised areas, which can be round or oval and of varying size (usually smaller than a thumbnail, but sometimes much larger). As they grow thicker, seborrheic keratoses may become dark brown to almost black and appear to be "stuck on" to the surface of the skin. The surface may feel smooth or rough. In lighter skin colors, they may be pink or any shade of brown. In darker skin colors, they may be any shade of brown, purple, gray, or blackish.

Self-Care Guidelines

No treatment is needed unless there is irritation from clothing, such as itching or bleeding.

Note that:
  • There is no way to prevent new seborrheic keratoses from forming.
  • Some lotions containing alpha hydroxy acids, salicylic acid, or urea may make the areas feel smoother with regular use but will not eliminate them.
  • Over-the-counter freezing techniques are available but are usually not effective.

When to Seek Medical Care

If a lesion on your skin is growing, bleeding, painful, or itchy, see your dermatologist or another medical professional. Similarly, consult a medical professional for any growth that is more than one color, that is dark brown or black, or that looks different than any of your other skin growths.

Seborrheic keratoses can be removed, but removal is considered a cosmetic issue and is usually not covered by insurance.


Removal can be accomplished with freezing (cryosurgery), scraping (curettage), burning (electrocautery), lasers, or acids. The dermatologist or other medical professional might conduct a biopsy if the growth looks unusual.
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Seborrheic keratosis
See also in: External and Internal Eye,Anogenital,Hair and Scalp
A medical illustration showing key findings of Seborrheic keratosis : Verrucous scaly papule
Clinical image of Seborrheic keratosis - imageId=76731. Click to open in gallery.  caption: 'An inflamed seborrheic keratosis showing a substantive pink and gray, stuck-on, verrucous plaque with keratotic plugs on the surface.'
An inflamed seborrheic keratosis showing a substantive pink and gray, stuck-on, verrucous plaque with keratotic plugs on the surface.
Copyright © 2023 VisualDx®. All rights reserved.