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What Is Seborrheic Keratosis?


A Seborrheic Keratosis (seb-o-REE-ik care-uh-TOE-sis), also known as SK or Seb Ker, is a benign (non-cancerous) growth of surface skin cells with pigment (color).

“They can appear in a person’s twenties but are more common as people age. The growths are often scaly and beige or brown, even turning black over time,” says Franziska Ringpfeil, M.D., Assistant Professor of Dermatology at the Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia and owner of Ringpfeil Advanced Dermatology in Haverford, PA. “Many people are embarrassed by their ugliness and think they look like warts or moles. They are sometimes called senile warts, senile keratoses, or considered the ‘barnacles of old age.’” Does that warty growth bothering you sound like SK? Check out the list below of signs and symptoms, assembled by Dr. Ringpfeil and Joel Gordon, M.D., Fellow of the American Academy of Dermatology and a dermatologist in Greenfield, MA. Then see a dermatologist for a proper diagnosis. SK and cancerous skin lesions, such as melanoma and basal cell carcinoma, can be easily confused. A dermatologist has specialized training to make the correct diagnosis, which could save your life. Any cancerous lesions should be treated before they increase in size or spread.

Signs and Symptoms

The Appearance of SK:

  • They are usually round or oval, with clearly defined borders. The borders can be regular or irregular.
  • They range in color and may appear white, flesh-colored, yellow, pink, grey, beige, dark brown, or black. The lesions in the brown spectrum are the most common. Sometimes, a lesion starts out beige and turns darker over time.
  • They can be flat or raised. Often lesions start out flat and become thicker and scalier, or warty-looking, over time. Sometimes, SKs are smooth and waxy, appearing to be stuck onto the skin, as though you can scratch them off. Don’t pick at them, though! Picking can make them bleed and cause an infection.

Location and Size of SK:

  • They can appear on your skin on any part of your body, except the palms, soles of the feet, or lips. They often appear on the scalp or face, especially around the temples or on the neck, shoulders, back, chest, or stomach. They are less commonly found on the buttocks or genitals.
  • The lesions can be scattered around your body, or they may cluster. Areas of friction, like the crease beneath the breasts where a bra can rub, are common sites of clustered SKs.
  • They range from a millimeter to a few centimeters wide. A lesion may also grow larger and thicker over time.

Symptoms of SK:

  • They are usually painless, though they can become irritated, inflamed, and painful.
  • The lesions can be itchy on their own, but often they become itchy, or may even bleed if they frequently rub against jewelry, clothing, or a seat belt. If they appear on a man’s face, they can interfere with shaving.

Age of Onset of SK and Number of Lesions:

  • They can begin to appear in a person’s 30s or even 20s, but the number of lesions increases with age, so people tend to notice SK lesions in their 40s and 50s.
  • Dermatologists reported in a 2014 survey that among the SK patients who come to see them, the average number of lesions each patient has is 17*.
  • Some people can develop a hundred or more of them if they are genetically predisposed to them.

*Data on File: Aclaris Therapeutics Inc. Survey of 594 dermatologists.

How Common Is It?

Most people develop a seborrheic keratosis at some point in life. According to the American Academy of Dermatology and the Society for Investigative Dermatology, the growths affect over 83 million people in the United States. In one Australian study published in the British Journal of Dermatology, 100% of people ages 51 and older had the condition. This study and other studies suggest that, in addition to increasing age, ultraviolet radiation (from sun exposure) plays a role in determining who will develop SK. Seborrheic keratosis equally affects men and women. People with a genetic predisposition to SK are more likely to develop the lesions when they are younger, and to have many of them over their lifetime. The condition is more common among Caucasians than other ethnicities. However, people of color are also prone to developing seborrheic keratosis lesions. In particular, African Americans are more prone to develop a variant of seborrheic keratosis, referred to as dermatosis papulosa nigra (or DPN), in which many smaller SK lesions are clustered on the face and around the eyes.

Home Remedy Cautions


Are There Any Do-It-Yourself Home Remedies for Removal of Seborrheic Keratosis?

On the Internet, people are eager to share ideas for home remedies and “natural” products to treat just about anything, and seborrheic keratosis (SK) is no exception.

Sites with inviting, earthy-sounding names feature chronicles of people who use home remedies to treat seborrheic keratosis. They advocate things like soaking cotton balls in apple cider vinegar and then taping them to their faces. (Presumably, these people go into hiding). Reported success is, as expected, mixed. On YouTube, a woman posts a video of a large facial SK that appears to have shrunken after dabbing drops of tea tree oil on it twice a day. Comments following the video include assurances that she will continue using the home remedy to treat the seborrheic keratosis until it is gone. Whether it’s the lure of the so-called “natural” approach, unhappiness with the currently available treatment options, or the desire to save money, some people would rather turn to their pantry than to their doctor when it comes to treating an SK. Many of these self-reliant types decide to go the do-it-yourself (DIY) route by trying over-the-counter wart treatments, even though SKs are different from warts.

First and foremost, it’s important to bear in mind that the home remedies mentioned “have never been tested for the treatment of seborrheic keratosis. So there is no scientific data to suggest they are safe and effective,” emphasizes Robert Brodell, M.D., professor and chair of the department of dermatology at the University of Mississippi Medical Center in Jackson.

What’s more, you shouldn’t be experimenting on your own with a lesion that should be checked out by a professional in the first place. “What if you’re wrong, and you’re trying to treat a melanoma instead of an SK?” says Deirdre Hooper, M.D., a dermatologist in private practice in New Orleans.

“I see many patients who try wart treatments first before they come in to see me,” says Dr. Brodell. “The salicylic acid in these products tends to chew into their lesions. So the patients manage to get irritated SKs, but they don’t get rid of them,” he says. “A wart treatment can take weeks to get to the point of irritating an SK lesion enough to loosen it somewhat,” says Dr. Brodell. The slow pace then spurs people “to overuse the treatment, increasing the chance of blistering and scarring,” points out Jerome Potozkin, M.D., a dermatologist in private practice in Danville, CA, and professor of dermatology at UCSF Medical School. One of Dr. Potozkin’s patients tried a caustic product that he bought online and ended up “burning a hole” in his back. “It was some kind of paste. I never saw the product, but he had an ulcerated crater on his back measuring about an inch in diameter.”

Some home remedies to treat seborrheic keratosis, such as lemon, apple cider vinegar, and coconut oil, contain citric and other natural acids that can irritate the lesion and possibly cause parts of it to dry up and crumble away (at least according to accounts on the Internet), but even if effective to some degree, this can take a very long time. Some people chart their progress over weeks and months, applying the fruits or vinegar multiple times a day. “Ultimately, such herbal remedies may not scar the skin, as wart treatments may, but they can be too weak to be effective,” says Dr. Hooper. Another herbal SK remedy mentioned on the Internet is tea tree oil. “This plant extract may act as a slightly stronger irritant than apple cider vinegar, for instance, but it can sometimes cause an immune system reaction known as allergic contact dermatitis,” says Dr. Potozkin. “Many of my patients have developed allergic contact dermatitis to tea tree oil,” he says. In these cases, an itchy or inflamed rash or bump developed around the SK.

In sum, it’s best to be wary of these DIY remedies and to consult your doctor about available treatments instead. You may spend a little more money upfront, but you’ll have greater peace of mind—not to mention a safe treatment that works.