Randy Jacobs, M.D. Patient Education

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Seborrheic Keratoses


What Causes Seborrheic Keratoses?
Seborrheic keratoses (SK's) are harmless, common skin growths that first appear during adult life.  As time goes by, more growths appear in older years. Some persons have a very large number of them. Seborrheic keratoses have been lightheartedly referred to as "Barnacles" because they tend to stick to the body. Seborrheic keratoses appear on both covered and uncovered parts of the body; they are not necessarily caused by sunlight, but do occur more commonly on sun-exposed areas. Seborrheic keratoses may occur as solitary papules, but more commonly occur in groups. The tendency to develop seborrheic keratoses is inherited. White people tend to develop seborrheic keratoses on the trunk, while black people tend to develop them on the face. In black people, seborrheic keratoses are referred to as dermatosis papulosis nigra.

Are They Cancer?
Seborrheic keratoses are harmless and virtually never become malignant. They begin as slightly raised, light brown spots. Gradually, they thicken and take on a rough, warty surface. They slowly darken and may turn black. These color changes are harmless. Seborrheic keratoses are superficial and look as if they were "stuck on" the skin. Persons who have had several seborrheic keratoses can usually recognize this type of benign growth, however, if you are concerned or unsure about any growth, consult your primary care physician.


Seborrheic keratoses can easily be removed in the office. The only reason for removing a seborrheic keratosis is your wish to get rid of it. Note: Under Medicare guidelines, the removal of a seborrheic keratosis is not covered unless the lesion is of medical necessity (interferes with vision, hearing, breathing), or is symptomatic (bleeding, itching, infected, inflamed). Medicare does not cover removal simply if the lesions are unsightly. Medicare does cover the evaluation of any lesion to determine if a lesion is or is not cancerous.