Patient Handouts : Seborrheic Keratoses

Seborrheic Keratoses

  • Seborrheic keratoses are the most common benign (noncancerous) growths in "older" adults. They are most common after the age of 30, but may occur at any age.
  • They usually start off flat, then become raised with time. As they become raised they often develop a warty or waxy texture.
  • They are most commonly found on the face, chest/breasts, shoulders and back, although they can occur anywhere on the skin.
  • Unlike moles, seborrheic keratoses grow on the "surface" of the skin and because of this they are often loosely attached and at times can fall off, especially if traumatized.
  • Many patients call seborrheic keratoses moles, but they are very different from common moles (melanocytic nevi). They are composed of a completely different cell type than moles and cannot develop into melanoma, unlike moles.
  • Seborrheic keratoses may vary in color from skin colored to brown or black. They often become darker as they grow.
  • They sometimes resemble warts, but unlike warts seborrheic keratoses are not caused by a virus and thus do not spread and are not contagious.
  • Seborrheic keratoses do not develop into skin cancer, but at times they can resemble melanoma and cause concern. Usually they can be easily differentiated from skin cancer simply by closely examining them, but on occasion a biopsy may needed to determine the diagnosis.


  • Because they are harmless, seborrheic keratoses generally require no treatment. However, if they are symptomatic (itchy, painful, or bleeding), then treatment is usually covered by insurance.
  • Some patients elect to have seborrheic keratoses treated for purely cosmetic reasons, and this would not be covered by insurance.
  • The most common treatment is to freeze with liquid nitrogen. This usually works well and usually leaves no mark once the treatment site has completely healed, however it can leave pale spots, dark spots, and can even leave a scar in rare instances. This is especially true for large lesions on the back or legs.
  • There is as yet no known way to reduce the development of seborrheic keratoses. Some individuals appear to develop more of these lesions than others due a hereditary tendency.