What are Sunspots and How to Treat Them?

Sunspots (solar lentigines) and solar keratosis (actinic keratosis) are both skin conditions caused by prolonged sun exposure, but they differ in their appearance, risk factors, and potential health implications.

Sunspots (Solar Lentigines):

These are benign, flat, pigmented spots caused by sun exposure and aging. They are a cosmetic concern but do not pose a health risk.

Solar Keratosis (Actinic Keratosis):

These are rough, scaly patches caused by prolonged UV exposure. These are of concern as they are felt to be pre-cancerous lesions, which means if left untreated they have the potential to turn into a skin cancer – commonly a squamous cell carcinoma.

The risk of a solar keratosis turning into a skin cancer is not known but the rate it thought to be about 5-20%. It is not possible to tell which will become a cancer and which will not, so all are identified, and treatment is advised.

Having solar keratoses also highlights that your skin has had enough sun exposure to cause DNA damage and the resulting development of pre-cancerous lesions, which in itself increases your individual risk of getting skin cancers.

What Causes Sunspots?

Sun spots are caused by UVA and UVB Rays from the sun. They most commonly appear due to excessive sun exposure over time, or numerous burning episodes. They most commonly appear on sun exposured areas such as the nose, temples, backs of the hands and decolletage.

Other cause of sunspots include:

  • Aging: As skin ages, it becomes less efficient at repairing damage caused by UV radiation.- Genetic Predisposition: Individuals with a family history of sunspots or pigmentation disorders are more likely to develop sunspots themselves.
  • Fair Skin: People with fair skin have less melanin and are more susceptible to the damaging effects of UV radiation.
  • Pregnancy and Hormonal Therapies: Hormonal changes during pregnancy (melasma) or from hormone replacement therapy can increase melanin production.
  • Skin Trauma: Injuries or inflammatory skin conditions can lead to increased melanin production in the affected areas.

The Role of UV Exposure in Sunspot Development

UV exposure is a primary factor in the development of sunspots, causing both direct and indirect damage to the skin.

UV Radiation Types:

UVA Rays: These rays penetrate the skin more deeply than UVB rays and contribute to skin aging and pigmentation changes. They can pass through glass and clouds, making them a constant threat to skin health all year round, every minute of the day.This is a reason you may need to protect your skin even if you cannot see the sun. Excessive UVA exposure over time can also cause skin cancers.

UVB Rays: These rays affect the outer layer of the skin, causing sunburns and play a key role in the development of skin cancer. They are stronger than UVA rays but do not penetrate as deeply. They cannot penetrate glass.

How to Identify Solar Keratosis?

Solar keratosis or Actinic Keratosis are usually flat or slightly raised red, tan or pink areas on the skin with a scaly or crusty surface that feels rough like sandpaper and does not soften. They can gradually increase in size and may disappear and then reappear during their early stages.

They commonly appear on sun exposed areas such as the face, scalp, temples, nose, ears, lips, hands and forearms.

Who is at Risk?

If you have had significant sun exposure, you are at risk of getting solar keratosis but they are commoner in those who:

  • Have fair skin
  • Over 40 years of age
  • Spent a lot of time outdoors
  • Have used solariums/tanning beds
  • Have had an organ transplant

Warning Signs of a Solar Keratosis Becoming a Cancer

Ensure you get a lesion checked by a Doctor at the Clinic if you notice:
Any change in a solar keratosis, but especially if it is becoming thicker, the top is developing more of a crust or thick horny growth, if it is tender or develops a sore or ulcer that doesn’t heal.

Treatment Options for Solar Keratosis

At MoS, we will help you identify lesions that are of concern and aim to give you up to date evidence based advise of the best treatment options.
If treated early almost all solar keratosis can be removed without turning into a skin cancer. Left untreated 2-5% can turn into a squamous cell carcinoma.

There are a number of ways MoS can treat solar keratosis. The options can be discussed with you during your consultation so that you understand the pros and cons of each, and which works with your lifestyle.

Treatments may be tailored to not only treat the visible lesions but also the surrounding damaged skin that may currently look normal but has the potential to also form pre-cancerous lesions. Unfortunately, the sun does not shine just on one spot, so the skin surrounding the lesion of concern is often damaged as well. It is possible to have up to 10 times as many invisible lesions as visible lesions. Treatments where the solar keratosis of concern PLUS the surrounding skin is treated are called Field Treatments.

Treatment options include but are not limited to:


Cryotherapy is a common and effective treatment for solar keratosis (actinic keratosis) that involves using liquid nitrogen to freeze and destroy abnormal skin cells. Cryotherapy is highly effective for treating solar keratosis. It is one of the most commonly used treatments due to its quick procedure time and minimal preparation.

Prescription Creams

There are a number of prescription creams available that can be applied daily to the lesions over a period of three days to three weeks. These creams work in different ways to kill the damaged cells within the lesions. They can cause the area treated to flare up and cause mild to severe redness, blistering and swelling. A benefit is that they can also treat lesions that are not visible and some early skin cancers i.e. field treatment.

Minor Surgery

Generally, not a usual measure for removing solar keratosis, but it may be recommended if a lesion looks to be showing early signs of a squamous cell cancer or is not responding to therapy as expected.

How to Prevent Solar Keratosis

Preventing solar keratosis involves protecting your skin from excessive sun exposure, as this condition is caused by long-term UV radiation damage. Preventative measures include:

  • Use Sunscreen regularly.
  • Wear Protective Clothing, including wide-brimmed hats, long-sleeved shirts and pants and UV-Blocking sunglasses.
  • Seek Shade by avoiding peak sun hours and use umbrellas and shade structures.
  • Avoid Tanning Beds as they also emit harmful UV radiation that can contribute to skin damage and increase the risk of solar keratosis.
  • Be Aware of Reflective Surfaces, such as Water, Sand, and Snow as these surfaces can reflect and intensify UV rays, increasing your risk of sun damage.
  • Get regular skin checks. More information about the importance of skin checks can be found here.
  • Check for Photosensitising Medications as some medications can make your skin more sensitive to the sun. If you are taking such medications, take extra precautions to protect your skin.
  • Maintain a Healthy Lifestyle with a healthy diet rich in antioxidants, Keep your skin hydrated by drinking plenty of water and avoid smoking.

Choosing the Right Sunscreen to Prevent Sunspots

Selecting the right sunscreen is crucial for preventing sunspots.

Ensure the sunscreen offers broad-spectrum protection, meaning it shields against both UVA and UVB rays. Choose a sunscreen with an SPF of at least 30. Higher SPF values provide greater protection, but it’s essential to apply it correctly and reapply as necessary. Look for sunscreens containing physical (mineral) blockers like zinc oxide and titanium dioxide, which provide broad-spectrum protection and are less likely to cause skin irritation. Chemical blockers like avobenzone, oxybenzone, and octocrylene are also effective but can sometimes cause reactions in sensitive skin. Finally, If you plan on swimming or sweating, choose a water-resistant sunscreen.Proper application is crucial for effectiveness. Don’t forget to reapply every two hours or immediately after swimming or sweating.

When to See a Dermatologist

Our doctor will assess your concerns. If dermatologist intervention is needed, we will provide you with a referral to your chosen dermatologist.

Book a Consultation for Personalised Care

Book in a medical consultation or full body skin cancer check with our GP who specialises in this area. A thorough consultation will be provided and if necessary, a personalised treatment plan developed.

Book Now

Book an appointment online or call the clinic on 5261 6171 to arrange an appointment.

Book an appointment online or call the clinic on 5261 6171 to arrange an appointment.

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