Seborrheic Keratosis
(Benign Skin Tumors)
Definition
Seborrheic keratosis is the presence of a benign (noncancerous) raised growth on the skin. Seborrheic means greasy (although often the growth is not greasy) and keratosis means thickening of skin. The growths arise from the top layer of skin and can have a ‘stuck-on’ look. These growths may look like warts. But, they do not extend deep into the skin or contain the viruses that cause warts.
Seborrheic keratoses are not contagious, do not spread, and will never turn into cancerous tumors. Therefore, they do not threaten your health. But, they can be irritating or cosmetically displeasing.
Skin Section with Seborrheic Keratosis
Causes
The direct cause of seborrheic keratoses is unknown. However, they are not caused by exposure to sunlight.
Risk Factors
Risk factors include:
- Being over 40 years of age
- Having close family members with the condition
Symptoms
Seborrheic keratosis:
- Can be located anywhere on body, but usually appear on the chest, torso, face, shoulders, or back
- Are typically yellow, tan, brown, or black
- Are elevated off the skin surface
- May have a rough or wart-like texture
- May have a pasted look, as if a blob of dirt or clay is stuck on the skin
- Usually have a round or oval shape
- Can be single or multiple growths
- May be itchy
- Can be irritated by clothing or jewelry and can bleed if picked or rubbed
Diagnosis
Since some seborrheic keratoses appear dark, they may be difficult to distinguish from pigmented growths that are prone to becoming cancerous. Therefore, it is very important that you have a doctor check and ensure that they are seborrheic keratoses. Doctors can usually make an accurate diagnosis upon examination of the skin growth, but a biopsy can be done to make sure in uncertain cases.
Treatment
Talk with your doctor about the best treatment plan for you. Because seborrheic keratoses do not pose a threat to your health, the best course of action may be to leave them alone. However, if they itch or become irritated, or if you feel they affect your appearance, they can be removed.
Treatment options include:
Topical Medications
Alpha-hydroxy lotions or mild steroid creams help with itching and irritation, but do not remove the lesion.
Cryosurgery: Removal by Freezing
Liquid nitrogen is used to freeze and destroy the cells of the seborrheic keratosis but leave the underlying connective tissue intact. This procedure leaves a crust that falls off after several days. There might be a flat scar or lighter colored skin.
American Academy of Dermatology
Family Doctor.org
Canadian Dermatology Association
Dermatologists.ca
American Academy of Dermatology. Seborrheic keratosis. American Academy of Dermatology website. Available at: http://www.aad.org/public/publications/pamphlets/common_seb_keratoses.html. Accessed November 11, 2010.
American Osteopathic College of Dermatology. Seborrheic keratosis. American Osteopathic College of Dermatology website. Available at: http://www.aocd.org/skin/dermatologic_diseases/seborrhiec_keraotos.html. Accessed August 22, 2005.
Mayo Clinic. Seborrheic keratosis. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/seborrheic-keratosis/ds00846. Updated November 25, 2008. Accessed November 11, 2010.
Last reviewed September 2011 by Ross Zeltser, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
