Seborrheic Keratoses

1.    What are Seborrheic Keratoses?

Seborrheic Keratoses are generally dark or brown wart-like growths appearing anywhere on the skin after the age of 30 and continuing throughout a lifetime.  The number of seborrheic keratoses varies from few to thousands per individual.  These growths may be due to sun damage, but also appear to be inherited.   Despite appearing dangerous, they are the most common benign growth of the skin.

2.    What Do Seborrheic Keratoses Look Like?

Seborrheic Keratoses begin as barely elevated, slightly bumpy, small plaques on the skin surface that may be either colored or not colored.  Over time, these grow into raised, warty plaques that appear as if “stuck on” to the skin surface, and are darkly pigmented or even black in darker individuals.  These later growths may be anywhere from 1 to 6 cm, and rarely may be itchy or tender. 

3.    Who Do Seborrheic Keratoses Affect?

Almost all individuals get sebhorreic keratoses, but they are rarely seen before age 30.  They are slightly more common among males than females. A unique variant of seborrheic keratoses occur in darker-skinned individuals, usually on the cheeks, close to the eyelids.  These are usually darkly-pigmented and occasionally “tag-like” growths, called dermatosis papulosa nigrans.

4.    What Causes Seborrheic Keratoses?

Seborrheic Keratoses are caused by an increase in the production of skin cells, including pigment cells.  The result is a thickening of the skin and a darker pigmenting of the tissue, as melanocytes increase and their product, melanin, pigments the involved area. 

5.    What Triggers Seborrheic Keratoses?

Unlike actinic keratoses, seborrheic keratoses are not completely caused by sun exposure.  They appear predominantly as a result of genetics, and little can be done to prevent their occurrence. In some cases, however, seborrheic keratoses may appear at the site of a severe sunburn, several years later.

6.    How Can My Seborrheic Keratoses Be Treated? 

Seborrheic Keratoses may be simply frozen off by applying liquid nitrogen, or shaven off if necessary with a short, painless procedure after numbing.  They may require multiple treatments with liquid nitrogen, but generally disappear after one or two applications.  After freezing, a blister may form over the wound, which may burst and crust while healing.  During a shave, only the elevated region and a few layers of skin beneath are removed, and rarely does the procedure result in an indent in the skin.  Differences in pigmentation are most often unobservable after the procedure.  Another approach for smaller seborrheic keratoses is to lightly remove them with an electric needle called a hyfrecator.  This can generally be done without need for topical numbing medication and usually requires only one or two treatments.  Dermatosis papulosa nigra, the variant of seborrheic keratoses more often seen on the cheeks of darker-skinned individuals, can also be treated using fine-needle hyfrecation.  In addition, recent reports have shown success in treating this condition with the Nd:YAG or the diode laser.  For more information on treatments for seborrheic keratoses or to schedule a skin check, please call and speak with a representative at the Berman Skin Institute.