Seborrheic Keratosis

What is seborrheic keratosis?

A seborrheic keratosis is a noncancerous skin growth. These common and benign growths typically occur as a person ages. Although seborrheic keratosis is not harmful, they can often resemble malignant skin growths. Because of the close resemblance to precancerous growths, it is important to receive an accurate diagnosis to rule out potential skin cancer or other skin conditions. 

Seborrheic keratosis is very common, affecting nearly 80 million Americans. Many people will have at least one growth in their life. The growths are typically brown, black, or tan and tend to appear on the face, neck, chest, or back. They do not require treatment, but you can have them removed for comfort or cosmetic reasons. 

What causes seborrheic keratosis?

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The exact cause of seborrheic is unknown. There may be a genetic link to the condition as this type of skin growth tends to run in families. In addition, developing one seborrheic keratosis makes you at risk of developing more. Since the growths are not contagious, you cannot spread seborrheic keratosis to others nor can you catch the skin condition from someone with seborrheic keratosis. 

Recent studies demonstrate how researchers are attempting to develop a more complete understanding of the noncancerous skin growths and work to identify the cause of the growths. Further knowledge may help people prevent these skin growths and avoid triggers that could cause them to grow. Further research into the condition and treatments is ongoing.

What are symptoms of seborrheic keratosis?

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Seborrheic keratosis growths are slow growing, so signs and symptoms may appear over time. The condition looks different for each person, but there are some common symptoms. The most common signs and symptoms include: 

  • Round or oval-shaped bumps with a rough or waxy feel
  • Slightly raised or flat growth with a scaly feel
  • Growths are typically brown, but they can also appear black, tan, yellow, white, or pink. 
  • Bumps in various sizes, ranging from very small to 1 inch in diameter
  • Growths that form in clusters with multiple bumps or a singular growth 

Growths can appear anywhere on the body and in any number. The only places growths will not form are the soles of the feet and palms. The most common locations of seborrheic keratosis include the scalp, chest, face, shoulders, abdomen, and back. 

Beyond the symptoms of the seborrheic keratosis growths themselves, the condition typically does not cause other symptoms. However, the growth clusters can cause itchiness or irritation and could catch on clothing. 

Are there risk factors or groups for seborrheic keratosis?

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Even without a known cause of seborrheic keratosis, there are risk factors that make a person more likely to develop skin growths. 

Age: Age is the main risk factor for seborrheic keratosis. People who are aged 50 and older are the most likely to form skin growths. They typically begin to appear in middle age and become incredibly common for people between 40 and 70 years old. It is very rare for younger people to experience seborrheic keratosis in their 20s or 30s.

Family History: Risk groups include those who have a family history of the condition. Approximately half of the cases occur in people who have family members with the condition. This connection indicates a possible genetic cause of the condition. 

Skin Tone: Seborrheic keratosis can occur in people of all skin tones. However, lighter-skinned people develop the condition more frequently. People with darker skin develop the condition, too. In some cases, seborrheic keratosis resembles dermatosis papulosa nigra on darker skin tones. 

Pregnancy: Pregnant people are at a higher risk of developing seborrheic keratosis during their pregnancy. 

Hormone Therapy: Those undergoing estrogen replacement therapy have a higher chance of developing the growths during their treatment. 

Sun Exposure: People with more direct exposure to the sun may be at a higher risk of developing the condition than people who stay protected from the sun. 

While these risk factors do make a person more likely to develop the skin growths, the condition is so common that even if these risk factors do not apply to you, you may still develop the condition over time. 

How is seborrheic keratosis diagnosed?

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To diagnose seborrheic keratosis, a doctor will assess your skin during an in-office appointment. Your doctor should be able to tell if you have the condition by a simple physical examination of the affected skin. You may also have to answer some questions about your medical history to assess your risk and likelihood of the condition. After the physical examination and overall health assessment, your doctor will likely be able to confirm a diagnosis

If your doctor is unsure about the diagnosis and thinks a different condition may be causing the growths, they may opt to perform a skin biopsy. After they remove the growth, they will examine the sample under a microscope to confirm the diagnosis. Your doctor could perform this procedure if they suspect the growth may be cancerous. In addition, you may receive a referral to a dermatologist for more specialized skin care. 

How is seborrheic keratosis treated?

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Seborrheic keratosis does not require any treatment or removal though the growths do not go away on their own. If you prefer to have the bumps removed or if your doctor thinks treatment or removal is the best option, your doctor can help determine the best method for removal. 

Your doctor may use one or a combination of the following removal methods: 

  • Cryotherapy: This treatment involves using liquid nitrogen to freeze the growth. After the freezing treatment, the bump should fall off within a few days or weeks. A possible downside of this treatment is the loss of pigment of the skin and may not work as well on more raised growths. 
  • Curettage (scraping): Your doctor will first numb the area of skin then use a scalpel to scrape off the growth. Sometimes doctors use curettage along with electrosurgery. 
  • Electrocautery: For this treatment, a targeted electrocurrent to burn the areas of seborrheic keratosis. Doctors tend to use curettage along with the electric current to shave off the dead skin. 
  • Shave excision: If your doctor needs to preserve a sample of the growth, they may do a shave excision in which they shave off a portion of the growth for lab examination. This way, they still remove the growth but without damaging a sample of the skin. 
  • Laser therapy: Lasers work by burning the growth. The lasers sterilize the wound and protect surrounding tissue. This treatment may leave the skin sore for a bit after the treatment. 
  • Prescription hydrogen peroxide: A recent FDA-approved treatment is prescription hydrogen peroxide. This treatment comes in an applicator pen that your doctor will apply during office visits. The direct application of the solution can cause mild skin reactions. 

Your doctor can help you assess which treatment option is right for you. Some treatments come with the risk of skin discoloration or scarring. While treatments that remove the growths prevent that particular instance of seborrheic keratosis from coming back, the bumps can appear on other parts of the body. 

Should you see a doctor for seborrheic keratosis?

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While seborrheic keratosis is not harmful and does not require treatment, you should see a doctor to confirm a diagnosis. You should also see a doctor if the bumps get irritated or start to bleed. In addition, if you notice rapid growth of the bumps and sores start to develop, these could be signs of skin cancer. Take these changes in your skin seriously and talk with your doctor. 

For most cases, you do not have to see a doctor immediately for seborrheic keratosis. If you notice any of the following occur, see your healthcare provider:

  • An existing seborrheic keratosis changes its appearance.
  • A new growth develops that does not resemble your seborrheic keratosis.
  • The growth develops an unusual color, like purple or reddish-black.
  • Many growths appear in a short period.
  • The skin is itching, bleeding, irritated, or painful.
  • The growth develops irregular borders that are blurred or jagged.

If you have concerns about your skin, it is better to be cautious and schedule an appointment with your doctor to have your skin checked. 

What is the outlook for people living with seborrheic keratosis?

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The outlook for people living with seborrheic keratosis is positive. Once you have seborrheic keratosis, new bumps may grow over time. If you have any growths removed, they will not grow back, but new bumps could appear elsewhere. You should confirm with your doctor that your diagnosis is seborrheic keratosis and not a precancerous growth. You should continually monitor your skin and see your doctor for regular checkups. 

Generally, this condition is not harmful and should not be cause for concern. Should you want to have the growths removed for your comfort, you can discuss the various treatment options with your doctor. Seborrheic keratosis does not interfere with your day-to-day activities and should not have a negative impact on your life.