Actinic keratosis and seborrheic keratosis are two skin conditions that often show up around middle age. Since actinic keratosis lesions can become cancerous, it’s best to get prompt treatment.

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Keratosis refers to an overgrowth of the protein keratin in the skin. This excess keratin can appear in skin lesions that resemble patches, warts, or moles.

Actinic keratoses tend to appear as smaller patches of rough-feeling skin, for example, while seborrheic keratoses may resemble a wart or mole.

These two conditions may have similar names, but there’s one major difference between the two: Actinic keratosis can become cancerous, while seborrheic keratosis is benign or harmless.

As you might imagine, this makes it important to know how to tell these lesions apart. If you have a hard time recognizing the difference between the two, here’s a quick rundown:

  • Actinic keratosis lesions often appear as rough, scaly patches that may show up in clusters. You’ll often notice these patches in areas that get a lot of sun exposure, like your arms, hands, or face.
  • Seborrheic keratosis tends to show up as a single lesion. These growths tend to be small, oval, thick, and raised. They can have a wart-like appearance.

Read on for an in-depth exploration of these two conditions, along with a few key signs you may want to connect with a dermatologist for diagnosis and treatment.

Since actinic keratosis is considered precancerous, it’s important to identify and treat it.

Here’s everything you need to know about this condition.

Signs and symptoms

Actinic keratosis lesions:

  • may appear as thick, rough, or crusty patches; sometimes, you might feel the change in skin texture rather than see it
  • are usually smaller than 2 centimeters (cm)
  • often appear on body parts that get a lot of sun (like your face, neck, scalp, arms, or hands)
  • often appear as the same color as surrounding skin, if you have darker skin
  • may appear pink on lighter skin, or have a tan, brown or gray hue
  • might burn or itch
  • may show up as a horn-like growth
  • can appear as scaly or colorless patches on your lips


Actinic keratosis usually develops as a result of sun exposure over time.

Your chances of developing this skin condition increase if you:

Treatment options

In the early stages, actinic keratosis is very treatable.

Your options for treatment include:

  • Electrocauterization: Electrocauterization involves burning the lesion with an electric current, which kills the affected skin cells.
  • Cryotherapy: Also called cryosurgery, this treatment involves applying a solution like liquid nitrogen to the affected area. This process freezes and kills the cells so the lesion scabs and falls off.
  • Curettage: This procedure involves scraping off the growth with a curette (a specialized surgical instrument). Your dermatologist may recommend this in combination with electrosurgery.
  • Chemical peels: Your dermatologist may apply a medical-grade chemical peel in-office to help remove the top layers of affected skin.
  • Topical medical therapy: Treatments like 5-fluorouracil can inflame and destroy the lesions.
  • Photodynamic therapy: Sometimes called phototherapy, this treatment involves the application of a photosensitive prescription medication solution (such as aminolevulinic acid) to the affected area. Your dermatologist will then direct a red or blue laser light over the treated area to help destroy the actinic keratosis cells.

These skin lesions are the most common form of benign lesion. If you notice them on your body, you might think they’re just another mole or wart.

In some cases, though, they can resemble precancerous or cancerous growths, such as melanoma.

Here’s how to recognize this type of skin growth.

Signs and symptoms

Seborrheic keratosis lesions:

  • may appear as round or oval-shaped, slightly raised growths
  • may seem “stuck on” to your skin
  • often have a waxy or scale-like texture
  • generally show up on the face, chest, back, stomach, or shoulders
  • typically won’t appear on the palms of your hands or the soles of your feet
  • often grow larger and thicker over time and can reach about 1 inch in diameter
  • often appear brown, black, white, or tan on light or dark skin
  • may cause itchiness or irritation, though these lesions usually aren’t painful


Researchers still don’t know exactly what causes seborrheic keratoses. The lesions don’t seem to be viral, bacterial, or contagious.

That said, the following risk factors may increase your chances of developing these growths:

  • Age: Seborrheic keratosis is uncommon in people under age 20. It often shows up in your 30s or 40s, and more lesions may appear as you get older.
  • Family history: This condition seems to run in families — the more relatives you have with this condition, the more likely you may develop it yourself.
  • Pregnancy or hormone therapy: Seborrheic keratoses may appear during pregnancy or estrogen replacement therapy.
  • Frequent sun exposure: Some evidence suggests these lesions may appear more often on sun-exposed skin, but they can also develop on skin not regularly exposed to sun.
  • Lighter skin: These lesions more commonly affect people with lighter skin, but it’s possible to still get them if you have darker skin.

Treatment options

Seborrheic keratosis often doesn’t require treatment. But if you dislike the way your lesion looks or feels, you can always talk with a dermatologist or other doctor about removal.

If your lesion is actually a precancerous or cancerous growth, you’ll need to have it removed. Your healthcare professional may recommend one of these procedures:

  • Cryosurgery
  • Electrosurgery and curettage: This procedure involves scraping off the growth with a curette (a specialized surgical instrument). Your dermatologist may recommend this in combination with electrosurgery.
  • Shave excision: Your dermatologist may shave off a sample of the growth to send it to a lab for analysis.
  • Ablation: This procedure involves using a specialized laser to vaporize the growth.
  • Nitric acid-zinc solution: One newer approach to treatment involves using a topical solution called Nitrizinc Complex. Emerging evidence suggests this treatment can safely shrink or totally eliminate the lesion, often within about 6 months.

Learn more about home remedies and treatments for seborrheic keratosis.

Any time your skin changes unexpectedly or you’re concerned about a lesion, a good next step involves getting an assessment from a dermatologist or other doctor.

Since actinic keratosis can sometimes turn into skin cancer, being vigilant about check-ups can help you lower your risk of skin cancer.

And even though seborrheic keratosis may not pose any danger to your health, it never hurts to have a professional confirm that your skin growth isn’t cancerous.

As a general rule, you’ll want to have a healthcare professional inspect your skin if:

  • You have a new growth.
  • The appearance of an existing growth changes.
  • A growth appears purple, blue or reddish or changes colors.
  • A growth has blurred or irregular borders.
  • A growth irritates you, bleeds, or causes pain.

Frequent sun exposure can increase your chances of skin cancer, but these tips can help lower your risk:

  • Wear sunscreen every day — rain or shine, indoors or out. Opt for sunscreen that has a SPF rating of at least 30, with broad spectrum protection to block both UVA and UVB rays.
  • Avoid tanning beds.
  • Avoid spending time outside between 10 a.m. and 4 p.m. UV rays are strongest in the middle of the day.
  • Protect your skin from UV rays by wearing hats, long sleeves, and pants.

Both actinic keratosis and seborrheic keratosis are skin conditions that show up as growths. But since actinic keratosis lesions can potentially become cancerous, it helps to know how to tell the difference between the two.

Seborrheic keratosis are raised lesions that tend to have a round or oval shape, while actinic keratosis typically shows up as dry patches in areas of skin that get frequent sun exposure.

Monitoring any changes in any moles or growths can help you get timely — potentially life-saving — treatment. When in doubt, it’s always wise to visit a dermatologist for an assessment.