What is Seborrheic Keratosis?

Seborrheic keratosis is one of the most common types of benign skin growth. Seborrheic keratoses, as they are known in the plural, are most common among older people, and many people develop these skin lesions later in life. As a general rule, a seborrheic keratosis does not represent a health threat, although some people choose to remove these growths for aesthetic reasons, or because they become a nuisance. You may also hear a seborrheic keratosis referred to as a “seb k,” since “seborrheic keratosis” is a bit of a mouthful.

These skin lesions can manifest in a variety of ways, and they can be found anywhere on the body. They may be brown, black, or light in color, and they typically start out as an area of raised skin. As the lesion develops, it may bulge out, and cracks and fissures can appear. The growth is often rough and hornlike, although it can also be smooth, with small granules below the surface of the seborrheic keratosis. Sometimes seborrheic keratoses feel slightly greasy to the touch, while at other times, they feel rough and dry.

The most distinctive feature of seborrheic keratoses is that they look as though they have been pasted onto the skin, or as though someone had an accident in a pottery class, spattering clay across an arm or leg. Some people call these lesions “barnacles,” because they do look sort of like barnacles, and, like barnacles, they seem as though they would be easy to pull off. Seb k's are also usually very itchy, especially in older people.

It is a good idea to see a doctor about any skin abnormality, to confirm the nature of the growth. A doctor can often identify seborrheic keratoses just by looking at them, but he or she might also request a biopsy to check the diagnosis. It is especially important to see a doctor if skin growths change color or shape, even if they were previously examined and classified as benign.

In some cases, a seborrheic keratosis becomes a nuisance, catching on clothing or jewelry, for example. These lesions can also look unsightly, especially on the face. In these instances, removal can be accomplished with an electrocautery, or through the use of liquid nitrogen. Doctors can also shave the growth off with a scalpel. Usually seborrheic keratoses bleed minimally, because there is little involvement with the deeper layers of the skin.