Seborrheic keratosis

A seborrheic keratosis is a benign form of skin tumor. The cause is unknown.

The condition commonly appears after age 40. It tends to run in families.

Symptoms of seborrheic keratosis are skin growths that:

• Are located on the face, chest, shoulders, back, or other areas, except the lips, palms, and soles
• Are painless, but may become irritated and itchy
• Are most often tan, brown, or black
• Have a slightly raised, flat surface
• May have a rough texture (like a wart)
• Often have a waxy surface
• Are round or oval
• May look like a piece of bee's wax that has been "pasted-on" the skin
• Often appear in clusters

Your health care provider will look at the growths to determine if you have the condition. You may need a skin biopsy to confirm the diagnosis.

You generally do not need treatment unless growths get irritated or affect your appearance.

Growths may be removed with surgery or freezing (cryotherapy).

Removing the growths is simple and generally does not cause scars. You may have patches of lighter skin where growths on the torso have been removed.

Growths usually do not return after they are removed. You may develop more growths in the future if you are prone to the condition.

These complications may occur:

• Irritation, bleeding, or discomfort of growths
• Mistake in diagnosis (growths may look like skin cancer tumors)
• Distress due to physical appearance

Contact your provider if you have symptoms of seborrheic keratosis.

Also contact if you have new symptoms, such as:

• A change in the appearance of the skin growth
• New growths
• A growth that looks like seborrheic keratosis, but occurs by itself or has ragged borders and irregular color. Your provider will need to examine it for skin cancer.

Benign skin tumors - keratosis; Keratosis - seborrheic; Senile keratosis; Senile verruca

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Requena L, Requena C, Cockerell CJ. Benign epidermal tumors and proliferations. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018:chap 109.

Updated by: Elika Hoss, MD, Assistant Professor of Dermatology, Mayo Clinic, Scottsdale, AZ. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.