Actinic Keratosis(Solar Keratosis)

This page is a hub. Use it to understand what AK is, then go deeper into:

• what AK looks like and why it forms, and
• the best treatment pathways to reduce your future risk.

Quick links

• Targeted skin spot check (1–3 spots)
• Full skin check
• Actinic keratosis treatment options
• Squamous cell carcinoma (SCC)
• How to reduce your chance of getting skin cancer again
• Skin cancer types

The 30-second overview

What is an actinic keratosis?

A sun-damaged patch where the skin cells have become abnormal. It often feels like sandpaper and can look pink, red, skin-coloured or brown.

Is it skin cancer?

AK is a pre-cancer. Many AKs stay stable or come and go, but a proportion can progress to SCC, especially if they become thicker or tender.

Why do doctors talk about “field damage”?

If you have multiple AKs, the skin around them has usually had years of UV exposure — so we often treat the whole zone (not just one spot) to reduce the overall burden and future risk.

When should I get an AK checked urgently?

Book an assessment sooner if an AK is:

• becoming thicker, more raised or lump-like
• tender, painful or persistently itchy
• bleeding, crusting repeatedly or ulcerating
• growing quickly
• on a high-risk site (lip, ear, scalp in a bald area)

These features can suggest progression towards SCC or another diagnosis that needs treatment.

Book a targeted spot check (1–3 spots)

How actinic keratosis develops

What’s happening in your skin

The outer layer of your skin — the epidermis — is built mostly from cells called keratinocytes. Ultraviolet (UV) light, whether from Australia’s intense sun or from solariums, carries enough energy to damage the DNA inside these cells. The occasional sunburn is usually repaired, but decades of cumulative UV exposure eventually outpace that repair, and some keratinocytes begin to grow and mature abnormally. An actinic keratosis is simply what that patch of abnormal cells looks like once it reaches the surface.

Because those cells are still confined to the surface layer, an AK is described as a pre-cancer — it sits at the earliest point on the same pathway that can lead to an invasive squamous cell carcinoma (SCC). Treating an AK early is, in effect, stepping in before that pathway has a chance to progress.

Why the visible spots are only part of the picture

By the time one rough patch is obvious, the surrounding sun-exposed skin has usually built up similar damage that you can’t yet see or feel. Doctors call this field cancerisation, or simply “field change.” Looking through a dermatoscope, we can often pick up far more abnormal skin than is visible to the naked eye.

This is the most important idea on this page. On its own, any single AK carries only a small risk. But a field of sun-damaged skin tends to keep producing new lesions — and the more AKs you accumulate, the greater the overall chance that one of them eventually progresses to SCC. That is why a heavy AK burden is managed as an ongoing plan rather than a one-off freeze, and it is the reason “field treatment” exists.

How we approach AK at The Skin Doctor

AK management isn’t just “freeze the spot.” The best strategy depends on whether you have:

• a single AK (often suitable for targeted treatment), or
• multiple AKs / widespread sun damage (often best managed with a “field treatment” plan).

Field or spot treatment?

The easiest way I’ve found to explain AK treatment to my patients is this.

Imagine a pristine field of brown dirt. You scatter weed seed across it — and that scattering is the equivalent of decades of sun exposure, the UV radiation gradually causing DNA damage to your skin cells.

Come back six to eight weeks later and you’ll see the large weeds from the side of the road. Those are the AKs visible to the naked eye — the pink, brown and rough precancerous patches.

But kneel down in the dirt and it’s a different story: there are countless tiny weeds and seedlings coming up everywhere. That’s what your doctor sees through the dermatoscope — the sub-clinical sun damage spread right across the field.

So if you want to deal with the weeds (the precancer), you have two choices:

• Pull out the biggest weeds — treat only the worst visible lesions. That’s spot treatment (for example, freezing an individual AK).
• Spray the whole field with weedkiller (RoundUp) — treat the entire area in one go. That’s field treatment, using laser-assisted photodynamic therapy or a cream like Efudix.

If you’re the patient who keeps getting “sunspots” every few months, it’s usually a sign you need a longer-term plan — not just repeated one-off treatments.

Learn about AK treatment pathways

When should we treat actinic keratosis?

Actinic keratoses, often called “sun spots” or “solar keratoses”, are areas of sun-damaged skin where some of the surface skin cells have become abnormal. They are considered precancerous because a small proportion can develop into squamous cell carcinoma, or SCC, over time. SCC is usually very treatable when found early, but it is still a true skin cancer and should not be ignored. ^(4,5,6)

The decision to treat an actinic keratosis depends on the balance between:

• the risk of that lesion progressing;
• the number of lesions and the amount of surrounding sun damage;
• whether the spot is changing, tender, thick, bleeding, ulcerated, or not healing;
• the patient’s overall risk, including previous skin cancers or immune suppression;
• the discomfort, downtime, cost, and temporary cosmetic effects of treatment.

Many people understandably think: “If this is precancerous, shouldn’t we treat it immediately?” Sometimes the answer is yes. But for very mild, flat, asymptomatic actinic keratoses, the decision is more nuanced.

One reason is that treating an actinic keratosis does not reset the skin back to brand-new, undamaged skin. Treatment removes or destroys the most abnormal cells, and the skin then heals from surviving normal-looking keratinocytes in the surrounding epidermis and from deeper skin appendages such as hair follicles. However, in chronically sun-exposed skin, many of these remaining normal-looking cells have also accumulated ultraviolet-related DNA damage. In other words, treatment can clear the visible precancer, but it does not erase decades of sun damage from the whole field of skin. ^(7,8)

This is why actinic keratoses often recur, or new ones appear, in the same general area over the following years, especially if ongoing UV exposure continues. Treating mild actinic keratoses at the very earliest stage may therefore mean repeatedly treating large field areas — such as the face, scalp, ears, forearms, or backs of the hands — every few years. These treatments can be very worthwhile, but they can also involve redness, crusting, pain, time off work or social activities, cost, and small risks such as infection, pigment change, or scarring. ^(1,9)

The other key point is that the risk of any one mild actinic keratosis turning into SCC within the next year or two is usually low. Published estimates vary because studies use different patient groups and definitions, but classic and systematic-review data suggest that the annual risk for an individual lesion is often well below 1 in 1,000 per year. In higher-risk populations, such as older patients with many actinic keratoses and previous skin cancers, the risk is higher; one Veterans Affairs study estimated about 0.6% at 1 year and 2.6% at 4 years for progression from a mapped actinic keratosis to SCC or SCC in situ. ^(4,5,6)

For these reasons, my usual approach is to actively treat actinic keratoses that are moderate, thickened, tender, growing, bleeding, ulcerated, persistent despite treatment, cosmetically troublesome, or occurring in a high-risk patient. For very mild, flat, asymptomatic actinic keratoses, observation and prevention can be reasonable, provided the patient understands the risks and returns for review if the lesion changes.

Prevention is still treatment of the underlying problem. The most important step is reducing ongoing UV exposure: daily broad-spectrum sunscreen, hats, protective clothing, shade, and avoiding unnecessary peak-UV exposure. In selected higher-risk patients, oral nicotinamide, a form of vitamin B3, can also be considered; it has evidence for reducing new actinic keratoses and non-melanoma skin cancers in high-risk immunocompetent patients, although it is not a substitute for sun protection or skin checks. ^(10,11)

Ultimately, the decision is individual. Some patients prefer to treat even mild lesions early. Others prefer to monitor mild change and reserve treatment for lesions that become thicker or more suspicious. Both approaches can be reasonable when the patient understands the trade-off between a low short-term risk of progression and the discomfort, downtime, and cost of treatment.

Explore actinic keratosis in detail

Actinic keratosis: explanation (what it is, what it looks like, what it means). If you’re trying to work out whether your spot is an AK and what it implies about your skin cancer risk, you’re in the right place.

Actinic keratosis treatment (reducing the burden of sun damage). If you already know you have AKs and want to understand treatment choices — including when “field therapy” is the smarter approach — see actinic keratosis treatment.

Not sure what to book?

• 1–3 specific spots you’re worried about — book a targeted spot check
• Many sunspots, lots of sun damage, or a history of skin cancer — book a full skin check