Seborrheic Keratosis Appearance

Seborrheic keratoses can appear anywhere on the body.  Some individuals may have just one or two, but it is far more common to have multiple seborrheic keatoses.  They may appear in clusters on the body in a “Christmas tree” pattern because of the skin cleavage lines.  They can range in color from white to black, but typically they start off as light tan and gradually darken to darker brown or nearly black.

The most consistent characteristic of seborrheic keratoses is their waxy, “stuck-on” appearance.  They look as if someone pasted them onto the skin, and in truth, they do not extend past the epidermis into the dermis.  They may take on a warty appearance with time, and on close examination, they can exhibit tiny white cysts and pore-like opening on the surface.

There are a few common variants of seborrheic keratoses that are typical of certain skin types.  Darker-skinned individuals can develop what’s called dermatosis papulosa nigra, which are small dark brown to black seborrheic keratoses clustered on the cheeks and sometimes neck and chest.  Lighter-skinned individuals may have small, white stuck-on papules on the lower legs that are referred to as stucco keratoses because of their resemblance to the building material.