Seborrheic keratoses (SKs) are common skin growths. These benign (non-cancerous) growths can occur almost anywhere on the skin. Some people get just one and others develop many. Having multiple SKs is more common.
Usually beginning as small, rough bumps, SKs tend to eventually thicken and develop a warty surface. Most are brown, but these growths range in color from light tan to black. Some SKs measure a fraction of an inch; others are larger than a half-dollar. A SK can be flat or raised. Sometimes the surface feels smooth.
What often distinguishes these growths from other lesions is a waxy, pasted-on-the-skin appearance. SKs can look like a dab of warm, brown candle wax on the skin. It also may resemble a barnacle attached to a ship. Either way, SKs tend to have that “stuck-on-the-skin” appearance.
Since SKs are benign, treatment is generally not necessary. There times, though, when these lesions should be examined by one of our dermatologists. Sometimes a SK grows quickly, turns black, itches, or bleeds, making it difficult to distinguish from skin cancer. Such a growth must be biopsied to determine if it is cancerous or not.
Occasionally, numerous new SKs develop suddenly. If this occurs, see one of our dermatologists. This can indicate a serious health problem.
Treatment may be recommended if the growth is large or easily irritated by clothing or jewelry. Sometimes, a SK is treated because the patient considers it unsightly.
Cryosurgery, electrosurgery, and curettage are the most common options for removing SKs.
Cryosurgery. Liquid nitrogen, a very cold liquid, is applied to the growth with a cotton swab or spray gun. This “freezes” the growth. The SK usually falls off within days. Sometimes a blister forms under the SK and dries into a scab-like crust that falls off. After the growth falls off, a small dark or light spot may appear on the skin. This usually fades over time. A permanent white spot is a possible side effect of this treatment.
Electrosurgery and Curettage. Electrosurgery involves anesthetizing (numbing) the growth and using an electric current to cauterize (burn) the growth. A scoop-shaped surgical instrument, a curette is used to scrape off the treated lesion. Stitches are not necessary. There may be minimal bleeding, which is controlled by applying pressure or a blood-clotting chemical. Sometimes only electrosurgery or curettage is necessary.