Kay Bishop, MD

These are referred to as seborrheic keratoses (plural) / seborrheic keratosis (single lesion).  The good news is that they are nothing to worry about.  The bad news is that we tend to get more and more of them with time.  These are common, benign (noncancerous) skin growths, that can range in color from light tan to almost black, and can range in size from very small to larger than an inch.  They are usually rough or waxy on the surface, and often look like they have been "stuck on," or splattered on the skin.  There is a genetic predisposition to form these.  Some people will get literally thousands of them, while others may have only rare isolated lesions.  They are generally asymptomatic, but occasionally become itchy or irritating.  The biggest medical concern regarding these lesions is that they can camouflage something else that you should be concerned about.  It is easier to overlook a melanoma if it is surrounded by other brown spots that may be more prominent than the skin cancer.  In contrast, melanoma skin cancer usually looks like it's in the skin, instead of on the skin.  A good rule to remember is that anything that looks different than anything else on your skin should probably be checked out (the "Ugly Duckling" rule).

Seborrheic keratoses can be removed, but removal does not prevent new lesions from coming.  If a person is genetically programed to get them in certain areas, it may not be too long after removal before new ones start to develop.  The most common method for removal is cryotherapy (freezing with liquid nitrogen).  This causes a blister to form underneath the seborrheic keratosis.  It is then best to let the blister dry up, let it heal underneath, and when the top of the blister comes off, so does the SK.  They can also be shaved off with a blade, or scraped off with an instrument called a curette.  This leaves a shallow sore that usually needs to be covered with a dressing until it heals.  Healing can occur within several days on the face, but can take several weeks elsewhere on the body.  Either of these methods can leave behind discoloration that can last for several weeks, or even a few months.  The discoloration is less likely to occur on the face, and more likely to occur with darker skin.  There are several different lasers that can be used to diminish the appearance of these lesions, but achieving complete removal is more difficult with most of the lasers than it is with the other two methods mentioned.  Cost is extremely variable.  In our office, we charge $85 for removal of up to 15 lesions, and $50 for each additional 10 lesions.  There is a soap bar called SKrub (Burke Pharmaceutials), that has variable success in diminishing the appearance of seborrheic keratoses.  This is available for $10.99.  Other cleansers or moisturizers with salicylic acid or alpha hydroxy acid (glycolic acid, lactic acid, etc.), can also be helpful.