Benign Skin Lesions

Seborrheic keratosis

What is seborrheic keratosis?
Seborrheic keratosis is one of the most common types of noncancerous skin growths in older adults. It's usually brown, black or pale and develops on the face, chest, shoulders or back. Typically waxy, scaly, and elevated, it commonly comes in multiple growths but may develop singly. These growths are not painful and don't require treatment.

What are the symptoms of seborrheic keratosis?
It looks like a waxy or wart-like growth, usually appearing on the head, neck or trunk of the body. Some characteristics of the growth are:
• Ranges in color from light tan to black
• Is round- to oval-shaped
• Has a characteristic "pasted on" look
• Is flat or slightly elevated with a scaly surface
• Ranges in size from very small to more than 1 inch across
• May itch

Do not rub, scratch or pick them because it could cause inflammation, bleeding and infection.

What causes seborrheic keratosis?
The exact cause of seborrheic keratoses is unclear. Genetics may play a role, and UV light may also affect development since they are common on sun-exposed areas.

When to seek medical advice?
See your doctor if:

Many growths develop over a short time. Normally, the growths appear one or two at a time over many years.

• The growths get irritated or bleed when your clothing rubs against them. You may want the growths removed.
• You notice sores or growths that grow rapidly, bleed and don't heal. These could be signs of skin cancer.

How to diagnose seborrheic keratosis?
Your doctor will inspect the growth and may recommend removal for examination under a microscope. If skin cancer is a concern, your doctor will take a sample of your skin for lab analysis.

How to treat seborrheic keratosis?
Treatment usually isn't necessary, but you may choose to get them removed because of irritation or cosmetic reasons. Removal of the growths is usually simple and not likely to leave scars. There are several options for removal:

• Freezing with liquid nitrogen (cryosurgery): may not work on large, thick growths, and may lighten the treated skin
• Scraping the skin's surface with a special instrument (curettage): sometimes used along with cryosurgery to treat thinner or flat growths, may be used with electrocautery.
• Shaving excision plus the feathering with a radio frequency device: this method can achieve the best result in the experienced hands. The lesion is shaved with a razor first and then feathered with a radio frequency device.

Unfortunately, most insurance companies and Medicare won't pay for the removal of seborrheic keratoses if done only for cosmetic reasons. Medical reasons for seborrheic keratosis treatment include intense itching, pain, inflammation, bleeding and infection.