Health Library

Seborrheic Keratosis

Definition

Seborrheic keratosis is a type of non-cancerous growth on the top layer of skin. These growths may look like warts.

Seborrheic keratoses are not contagious, do not spread, and do not turn into cancerous tumors. In most cases, treatment is not required.

Causes

The direct cause of seborrheic keratosis is unknown, but it may be linked to genetics.

Risk Factors

Seborrheic keratosis is more common in people aged 40 years and older and in those with a family history.

Symptoms

Seborrheic keratosis are thick growths that may:

  • Look yellow, tan, brown, white, or black
  • Be waxy or look like warts
  • Be round, flat, or oval in shape
  • Be itchy when irritated by clothing or jewelry
  • Appear anywhere on the skin

Some people have one lesion, but it is more common to have many.

It may be hard to detect the difference between seborrheic keratosis and melanoma, a potentially fatal skin cancer. It is important to see visit the doctor anytime new or changing skin lesions are noticed.

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor can usually make a diagnosis upon examination of the skin growth. You may need further testing, such as a skin biopsy, to rule out other skin conditions.

Punch Biopsy of the Skin
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Treatment

Seborrheic keratoses do not pose a health threat. The best course of action may be to leave them alone. If they itch or become irritated, or if they are unsightly, they can be removed.

Treatment options include:

Medications

Topical corticosteroids may be advised.

Surgery

If a decision is made to remove the seborrheic keratoses, surgical options include:

  • Freezing the growth, which falls off a few days later
  • Removal with a razor or scalpel
  • Laser surgery to burn the growth off

Prevention

There are no current guidelines to prevent seborrheic keratosis.

Resources

American Academy of Dermatology
http://www.aad.org

Family Doctor—American Academy of Family Physicians
http://familydoctor.org

Canadian Resources

Canadian Dermatology Association
http://www.dermatology.ca

The College of Family Physicians of Canada
http://www.cfpc.ca

References

Common benign skin lesions. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T908545/Common-benign-skin-lesions. Updated July 24, 2017. Accessed September 1, 2017.

Seborrheic keratosis. American Academy of Dermatology website. Available at: http://www.aad.org/dermatology-a-to-z/diseases-and-treatments/q---t/seborrheic-keratoses. Accessed September 1, 2017.

Seborrheic keratosis. American Osteopathic College of Dermatology website. Available at: http://www.aocd.org/?page=SeborrheicKeratoses. Accessed September 1, 2017.