Actinic keratosis: what therapy actually involves

• A rough patch that is growing, thickening, becoming raised or tender Promptly

  Change is the signal that a precancer may have become a squamous cell carcinoma. Tenderness, induration and rapid growth are the specific features clinicians act on, and a biopsy is a small procedure with a lot of information in it.

• A sore or scaly spot that bleeds, ulcerates or simply never heals Promptly

  Skin repairs itself on a schedule of weeks. A lesion that has not healed in six to eight weeks is outside normal biology and needs an examination, whatever it turns out to be.

• A persistent scaly or crusted patch on the lower lip or the ear Promptly

  Squamous cell carcinoma at these sites spreads more readily than elsewhere, so the same lesion earns a faster appointment for sitting there. A 'chapped' patch of lip that months of balm has not fixed belongs in this category.

• New or multiplying rough patches while on immunosuppressant medication Promptly

  Immunosuppression accelerates the whole pathway from sun damage to skin cancer. Transplant recipients and others on long-term immunosuppressants should have a low threshold for review and, ideally, a standing surveillance arrangement rather than ad-hoc appointments.

• A first rough, scaly patch that keeps re-forming in the same place Worth raising

  Not an emergency — but it is a biopsy-able, treatable marker of sun damage that deserves a diagnosis rather than a permanent seat in your exfoliating routine. Booking a routine skin check converts an unknown into a plan.

Decades of ultraviolet exposure leave keratinocytes — the skin's main cells — carrying accumulated DNA damage, classically in the p53 gene that normally acts as the cell's brake. An actinic keratosis is a patch where damaged cells have begun to grow abnormally but have not yet become invasive cancer: rough, scaly, often easier to feel than to see, on exactly the skin that caught the most sun — face, ears, scalp where hair has thinned, forearms, backs of the hands. Two facts frame everything else on this page. First, the risk that any single patch progresses to squamous cell carcinoma in a given year is small. Second, these lesions almost never arrive alone: they mark a whole field of sun-damaged skin producing them, so the meaningful number is not one small risk but that risk multiplied across many lesions and many years. That is why clinicians take an unimpressive-looking scaly spot more seriously than its appearance suggests — and why treatment so often addresses the field rather than the single spot.

Who this page is for

Anyone who has noticed a rough, scaly, sandpapery patch that flakes off and re-forms in the same place on sun-exposed skin; anyone already diagnosed who wants to understand why one clinician froze a lesion and another prescribed a cream that made their whole forehead red; and anyone with years of outdoor work or sun behind them who is wondering what surveillance of their own skin should look like from here. It is also for the person quietly exfoliating the same spot for a year — the patch that keeps coming back is the one this page is about.

This page maps the territory — it does not diagnose anything on your skin. Several things produce rough or scaly patches: seborrhoeic keratoses, which are harmless and extremely common with age; patches of eczema or psoriasis; and squamous cell carcinoma itself, which an actinic keratosis can resemble closely. Distinguishing them is a visual and tactile skill built on thousands of examples, sometimes needing dermoscopy or a biopsy, and it is precisely what the appointment is for.

Clinicians describe actinic keratosis less by a formal stage than by pattern: how many lesions, how thick, and whether the surrounding skin is itself damaged. Those three observations drive every treatment choice on this page.

What changes the picture

A suppressed immune system

People taking long-term immunosuppressants — most notably after an organ transplant — develop actinic keratoses earlier, in greater numbers, and with a substantially higher rate of progression to squamous cell carcinoma. For this group the whole page shifts one notch up in urgency: surveillance is more frequent, treatment thresholds are lower, and this is managed as an ongoing programme rather than an occasional errand.

A previous skin cancer

A history of squamous or basal cell carcinoma marks you as someone whose sun damage has already produced cancer once, which changes the surveillance conversation and is exactly the group in which preventive measures — rigorous photoprotection, and sometimes oral nicotinamide — have their best evidence.

Fair skin and a high-exposure life

Fair skin that burns easily, decades of outdoor work, a sunbelt retirement or a tanning-bed history all load the same dice. None of it can be undone, which is worth saying plainly: the point of knowing your exposure history is not regret but calibration — it tells you and your clinician how hard to look and how often.

Where the lesions are

Lip and ear lesions carry higher stakes, because squamous cell carcinoma at those sites metastasises more readily than on most skin. A scaly patch on the lower lip or the rim of the ear earns an appointment faster than the same patch on a forearm.

What else looks like this

Seborrhoeic keratosis

The great impersonator of ageing skin — waxy, stuck-on-looking, often darker, and completely harmless. Enormously common, frequently mistaken for something sinister in both directions, and one of the main reasons the diagnosis is made by a trained eye rather than a mirror.

Squamous cell carcinoma

The one that matters. A thickening, tender, growing or ulcerating lesion on sun-damaged skin may no longer be a precancer. This is not a distinction to attempt at home — it is the reason thick or changing lesions get biopsied.

Basal cell carcinoma

The commonest skin cancer, sharing the same sun-exposed territory — often a pearly bump or a flat scaly patch that slowly grows or bleeds and never quite heals.

Eczema or psoriasis patches

Inflammatory patches can look similar but usually itch, respond to their own treatments, and come and go. An actinic keratosis mostly just persists — rough, indifferent, and in the same spot every time you check.

The most useful thing you can do before an appointment is nothing destructive: do not scrub, pick, freeze with a home kit, or apply an acid to an undiagnosed rough patch. A partially treated lesion is harder to assess, and the reassuring-feeling ritual of exfoliating the roughness away — it always returns — is the single most common way these lesions buy themselves another year of not being looked at.

What follows describes what clinicians actually do about actinic keratosis, so that an appointment — and the sometimes alarming aftermath of field treatment — makes sense. It is deliberately not a menu to order from: lesion-versus-field decisions turn on an examination.

The central decision is spot versus field. A few discrete lesions are usually destroyed individually in clinic; many lesions on damaged skin are usually treated as an area, with a prescription cream or photodynamic therapy. Most people with more than a few lesions will meet both approaches over time, and often in combination — neither is a failure of the other, and they answer different questions.

The strength chips below describe how well each option has been tested, not how well it would suit you. 'Backed by large randomized trials' and 'backed by smaller studies' are our own readings of the trials cited at the foot of this page, in plain words rather than the letter grades clinical references use.

1. 1

   Lesion-directed therapy in clinic

   Physically destroying individual lesions, most commonly by cryotherapy — a precise spray of liquid nitrogen. Quick, effective for discrete lesions, and done in the same visit as the diagnosis. Thick or atypical lesions may instead be scraped (curettage) or biopsied first, because destroying a lesion also destroys the chance to examine it under a microscope.

   • Cryotherapy (liquid nitrogen) backed by smaller studies The workhorse, and its results depend on how long the freeze lasts: in a prospective series of 421 lesions, complete response was 39% where the freeze ran under five seconds and 83% where it ran over twenty. Stings sharply for seconds; blisters or crusts over days; heals in one to two weeks. Around a third of cleared lesions leave a pale mark, which is the trade-off nobody mentions beforehand.
   • Curettage limited evidence Scraping under local anaesthetic — used for thicker lesions, and it can provide tissue for pathology when there is any doubt.
   • Shave or punch biopsy Not a treatment but the step that precedes one whenever a lesion is thick, tender, growing or otherwise unwilling to behave like a simple actinic keratosis.

   What to expect

   A brief, sharp sting per lesion, then a blister or crust that heals over a week or two. A treated lesion that grows back in the same spot is important information rather than bad luck — recurrence after destruction is one of the triggers for biopsy.

   Who it's for

   One to a handful of discrete lesions, and any lesion a clinician wants gone today.

   In pregnancy

   Cryotherapy is a physical treatment with no systemic drug exposure and is generally considered usable in pregnancy — one of several reasons lesion-directed treatment is the default when field creams are off the table.

2. 2

   Field-directed prescription creams

   A course of a prescription cream applied to the whole damaged area — forehead, scalp, forearm — to clear visible lesions and the subclinical ones forming between them. This is the tier people are least prepared for, because the effective ones work by provoking a brisk inflammatory reaction: the area gets red, raw and crusted before it heals clearer.

   • Fluorouracil (5-FU) cream backed by large randomized trials The best-evidenced option, and the one with the most to show for itself: in a 2019 head-to-head across four field treatments it was clearly the most effective at twelve months, it held its lead in a community-practice cohort of 5,700 patients, and a randomised chemoprevention trial found a single course cut surgery for squamous cell carcinoma over the following year. The fierce redness during a course is the drug finding damaged cells, not an allergy — but nobody should discover that mid-course from a mirror.
   • Imiquimod cream backed by large randomized trials Recruits the immune system against damaged cells rather than poisoning them directly, and that difference shows up late: in a three-arm randomised comparison, imiquimod had the highest sustained clearance a year after treatment and the cosmetic outcomes investigators rated best, despite clearing fewer lesions than fluorouracil at the end of the course. Produces its own inflammatory reaction, occasionally with brief flu-like symptoms.
   • Tirbanibulin ointment backed by large randomized trials The newest option, approved in December 2020 on two phase 3 trials in which a five-day course cleared all lesions in roughly half of participants. A much shorter course than the others, a generally milder reaction, a considerably higher price — and, being recent, no decade of follow-up behind it.
   • Diclofenac gel (prescription strength, for this indication) backed by smaller studies An older, gentler field option run over about three months, with more modest clearance. Its usefulness now is mostly in sequence rather than alone — and in being tolerable enough to finish, which is not nothing on a face.

   What to expect

   Days to weeks of genuinely unattractive skin — red, scaly, crusted — followed by healing over one to two weeks after the course ends. Clinicians increasingly photograph the field before starting so that the mid-course state can be compared against something. Plan courses around events; a forehead in week two of fluorouracil is not subtle.

   Who it's for

   Multiple lesions in one area, field change, and people whose new lesions keep arriving — treating the field addresses the ones you cannot see yet.

   In pregnancy

   Fluorouracil is contraindicated in pregnancy, and the field agents in general are avoided — anyone pregnant or planning to be should say so before a course is prescribed, and lesion-directed options fill the gap.

3. 3

   Photodynamic therapy

   A clinic-administered field treatment: a photosensitising cream is applied to the area, allowed to absorb into damaged cells, then activated with a specific light source, destroying the cells that took it up. It concentrates the entire treatment reaction into a clinic visit and the days after it, rather than weeks of home application.

   • Conventional (red-light) PDT backed by large randomized trials Effective for field change; the activation period can be genuinely painful on densely damaged skin, which clinics manage in various ways.
   • Daylight PDT backed by smaller studies The same principle using daylight as the light source — substantially more comfortable, used where climate and season allow.

   What to expect

   Burning or stinging during light activation, then redness and peeling for about a week. Strict photoprotection of the treated area for the following days is part of the treatment, not an optional aftercare nicety.

   Who it's for

   Field change, people who prefer a supervised one-visit treatment over weeks of self-applied cream, and sites where a controlled reaction is worth the clinic time.

   In pregnancy

   Generally deferred in pregnancy — not because of a specific known harm, but because elective treatment of a slow condition is easy to postpone, and that is the default logic clinicians apply.

4. 4

   Combining approaches, deliberately

   Increasingly this is not a choose-one menu. Freezing the visible lesions and then treating the skin around them; pairing a field cream with a second agent that amplifies it; running a field cream into photodynamic therapy. The reasoning is that the two halves of the problem — the lesions you can see and the damaged field between them — do not answer to the same tool, and a combination reaches both in one campaign rather than across three separate years.

   • Cryotherapy first, then a field agent backed by smaller studies In a trial of cryosurgery followed by a course of diclofenac gel, 46% of participants cleared completely against 21% with cryosurgery alone. The freeze takes what is visible; the cream works on what is forming around it.
   • Fluorouracil with calcipotriol backed by smaller studies Adding calcipotriol — an unremarkable vitamin D analogue — appears to recruit an immune response alongside fluorouracil's direct effect, and a 2024 systematic review found the pair cleared more lesions on the head and neck than fluorouracil alone. It is also the combination behind reports of dramatically shorter courses, though how short is not yet settled.
   • Fluorouracil into photodynamic therapy backed by smaller studies A split-site study applying fluorouracil before photodynamic therapy on one side of the face found better clearance at six and twelve months than photodynamic therapy alone on the other.
   • Photodynamic therapy, then imiquimod backed by smaller studies Sequential treatment beat either alone in a randomised pilot — while photodynamic therapy on its own was the arm participants rated most satisfactory. Efficacy and tolerability point different ways here, and the choice is genuinely yours to discuss.

   What to expect

   More reaction rather than less, and a longer schedule to plan around: two mechanisms in sequence usually means a brisker inflammatory phase than either alone. What it buys is a better chance of the field still being clear a year later.

   Who it's for

   Dense field change, lesions that keep returning after single-agent courses, and situations where getting one campaign right matters more than getting it over with quickly. Which pairing gets used is decided at the appointment — direct comparisons between combinations barely exist, so this is an area where clinicians are reading the same thin evidence you would be.

   In pregnancy

   Every pairing here contains at least one agent avoided in pregnancy, so combinations are deferred rather than adapted; cryotherapy and photoprotection continue unchanged.

5. 5

   When a lesion refuses to clear

   A patch that survives adequate treatment, or returns promptly in the same spot, changes the question from how to clear it to whether it is what everyone assumed. Failure to respond sits alongside thickening, tenderness, bleeding and rapid growth on the standard list of reasons to biopsy — because a proportion of lesions that look and behave like actinic keratoses are already squamous cell carcinoma under the microscope. Only after that question is answered does the conversation return to how to remove it.

   • Biopsy The step that resolves the question rather than treating it. In a series of 271 clinically diagnosed actinic keratoses sent for pathology, the clinical diagnosis was right about 91% of the time and roughly one lesion in twenty-five turned out to be an invasive squamous cell carcinoma. In people with a previous skin cancer, a small study found the proportion higher still.
   • Curettage or surgical excision limited evidence Physical removal for thick, hyperkeratotic or stubbornly recurrent lesions — and the option that produces tissue for pathology while it treats. Recommended on guideline consensus rather than trial evidence, which is honest rather than damning: nobody randomises this.
   • Ablative laser resurfacing backed by smaller studies For widespread damage across a face or bald scalp, resurfacing the whole area has held recurrences off for years in follow-up series, and beat a fluorouracil course on recurrence at twelve months in one randomised comparison. The cost is a substantial healing period, and hypopigmentation is a recognised outcome rather than a rare mishap.

   What to expect

   A biopsy is a few minutes, a stitch or none, and a wait of a week or two for the result — a wait that is worth naming, because it is the unpleasant part. What follows depends entirely on what comes back, and the great majority of these results are reassuring.

   Who it's for

   Any lesion that has not cleared after appropriate treatment, anything recurring in a treated site, and any patch whose behaviour has changed regardless of how ordinary it looks.

   In pregnancy

   Diagnosis is never deferred in pregnancy. Biopsy under local anaesthetic and physical removal both go ahead on the usual timetable; only elective resurfacing waits.

6. 6

   Prevention, chemoprevention and surveillance

   The tier that runs underneath all the others, and the only one with an over-the-counter component. Rigorous daily photoprotection reduces new lesions; oral nicotinamide has randomised-trial evidence for reducing new actinic keratoses and keratinocyte cancers in people who have already had them; and a surveillance rhythm — professional skin checks plus knowing your own skin — is what catches the lesion that misbehaves.

   • Daily broad-spectrum sunscreen backed by large randomized trials The single evidence-backed aisle intervention on this page, and it was established properly: two Australian randomised trials found daily sunscreen both reduced new lesions and increased remission of existing ones against discretionary use. Its effect is on the next decade's lesions, which is exactly why it feels like it is doing nothing.
   • Oral nicotinamide (vitamin B3) backed by large randomized trials In a 2015 phase 3 trial in people with prior skin cancers, 500 mg twice daily reduced new keratinocyte cancers and actinic keratoses. It is sold over the counter — but whether it is worth taking, at what dose, and for whom is a conversation to have with the clinician who knows your history; a later trial in transplant recipients did not show the same benefit.
   • Scheduled skin checks limited evidence The interval is set by your history — number of lesions, prior cancers, immune status. The point of a schedule is that it removes the decision from you on any given busy month.

   What to expect

   Nothing dramatic, ever — prevention is invisible when it works. The realistic promise is fewer new lesions and earlier catches, not a fixed endpoint.

   Who it's for

   Everyone on this page, permanently, which is precisely what distinguishes this condition from most of dermatology.

   In pregnancy

   Sunscreen and surveillance carry over unchanged. Nicotinamide in pregnancy is a clinician conversation like any supplement taken at pharmacological doses.

No doses appear here, deliberately, and no ranking beyond what trial evidence supports. Whether your skin needs a freeze, a field course, light-based treatment or just a schedule is a judgement made by someone looking at all of it at once — and a plan that treats lesions without a surveillance rhythm behind it is half a plan.

The appointment an actinic keratosis prompts is rarely about that one lesion. It is the occasion on which the rest of a sun-exposed skin surface gets professionally examined — and that examination is where the real value sits.

None of this is a list of things that will happen — most actinic keratoses never become anything worse. It is the reason the appointment matters beyond the lesion that booked it: the same sun that made one patch made the whole surface, and the whole surface is what gets looked at.

Everything above describes an immunocompetent adult with sun-damaged skin and no particular hurry. Three situations change that picture — and in two of them what changes is that the threshold for acting drops sharply.

Here is where the aisle genuinely earns its place — not treating anything, but preventing the next lesion and keeping treated skin comfortable. On this page, unusually, the supporting role has better trial evidence than most products on this site can claim for anything.

The job of everything here is photoprotection and barrier comfort. Ultraviolet exposure is the entire cause of this condition; blocking it is the one intervention that changes the trajectory, and it works on skin that already has lesions by reducing the arrival of new ones.

• Products graded for sun damage
• Sunscreens
• Lip care

Treatment works: individual lesions clear reliably, and field treatment leaves treated skin measurably clearer for years. What treatment does not do is change the skin's history — the field that produced these lesions retains the damage it accumulated, and new lesions arriving over the years ahead is the expected pattern, not a sign that anything failed. The honest framing is a maintenance relationship: periodic checks, occasional treatment, daily photoprotection, ongoing. The other expectation worth setting concerns field creams specifically. An effective fluorouracil course makes the treated area look considerably worse before it looks better — red, crusted, raw — and people who were not warned reasonably conclude something has gone wrong and stop. Knowing the reaction is the mechanism, not a side effect, is the difference between completing a course and abandoning it at its least attractive midpoint.

• Field-treatment reactions are expected, not allergic — but confirm with the prescriber what the normal range looks like and what would count as too much
• Complete the prescribed course even once the skin looks angry; stopping at peak redness is the commonest way an effective course gets recorded as a failure
• A treated lesion that recurs in the same spot is a finding to report, not a reason to re-book the same freeze — recurrence is one of the standard triggers for biopsy
• Daily sunscreen on the affected territory is part of the treatment plan, not general wellness advice appended to it
• Keep the surveillance schedule even in years when nothing seems to be happening — 'nothing happening' confirmed by examination is the schedule working

Worth going back if a treated lesion recurs, if any lesion becomes tender, thickened, raised or starts bleeding, if new lesions are arriving faster than your check schedule anticipates, or if a field-treatment reaction seems beyond what you were told to expect. And if you were treated once and given no follow-up interval, going back to ask for one is a legitimate appointment in itself.

In most systems this starts with a family doctor or GP, who can examine the lesion, treat straightforward actinic keratoses — many GPs offer cryotherapy — and refer onward when there are many lesions, diagnostic doubt, or a lesion that needs a biopsy. Dermatology referral is usual for field change, thick or atypical lesions, lip and ear lesions, and anyone immunosuppressed, for whom a standing dermatology arrangement rather than one-off visits is the norm. Waits for routine skin checks vary widely; a lesion with any red-flag feature above should be flagged as such when booking rather than joining the routine queue.

Cost and access

Cryotherapy is quick, widely available and inexpensive as procedures go, and generic fluorouracil cream is one of dermatology's cheaper prescriptions — this is not, at the standard tiers, an expensive condition to treat. Costs climb with the newer options: tirbanibulin is priced far above generic field creams, and photodynamic therapy involves clinic time that is billed and covered variably. In insurance systems, treatment of actinic keratosis is generally covered as medical rather than cosmetic care — a distinction worth knowing, because reluctance to 'spend on skin stuff' keeps some people from a treatment their coverage already includes.

A family doctor can reasonably diagnose and freeze typical actinic keratoses and is often the right first stop. Asking for dermatology referral is reasonable when lesions are numerous or keep returning, when anything is thick, tender or growing, when the lip or ear is involved, or when you are immunosuppressed. If a lesion is being watched rather than treated, ask what specifically would change the plan — 'keep an eye on it' is only a plan when both parties know what they are watching for.

Free, ours, and no account needed. On a page whose whole pathway is 'be assessed, then keep watch', the useful tools are the ones that make watching systematic and the appointment well-armed.

• ABCDE Mole Self-Check

  Surveillance between professional checks is half the plan on this page, and a structured way of looking beats staring anxiously at everything. Built for moles, but the habit of systematic self-examination is exactly what this condition asks for.

• Mole Map

  Sun-damaged skin produces new spots constantly, and 'was that there in spring?' cannot be answered from memory. Pin the spots being watched, date what changes, and print the map for the next skin check.

• Skin Cancer Risk Tier

  AKs are a marker of field damage, and field damage makes surveillance a risk-tier question. This walks the established risk factors once, honestly, so the check-schedule conversation starts from a tier rather than a guess.

• Progress Photo Tracker

  Change over time is the single most useful thing you can report about a lesion, and memory is a terrible instrument for it. Dated photos with consistent framing turn 'I think it might be bigger' into evidence.

• Sun Safety Tool

  Photoprotection is the one part of this page you administer yourself, permanently. This helps turn it from a resolution into a routine.

• Derm Visit Prep

  The appointment is the pathway here, so arriving with your history, medication list and lesion notes organised is worth more than on almost any other page.

Actinic keratosis attracts a long tail of half-treatments — resurfacing devices, peels, retinoid creams, supplements. Some carry real trial evidence and a narrow place; one of them was tested honestly and failed in the most instructive way available. Sorting them is how the patience gets spent on the tiers that work.

• Topical adapalene backed by smaller studies

  A randomised trial of nine months of adapalene gel found at least moderate improvement in about two-thirds of participants against a third on vehicle. Genuine, but slow and partial next to a field agent, and nine months is a long time to spend on partial. Its place is alongside a plan rather than instead of one.

• Chemical peels (trichloroacetic acid, Jessner's solution) backed by smaller studies

  A medium-depth peel does clear these lesions — an older split-face study put a single Jessner's/TCA peel level with three weeks of fluorouracil at twelve months, with both groups accumulating new lesions after that. A more recent randomised comparison found photodynamic therapy clearly better than a 35% TCA peel. Reasonable in experienced hands where the alternatives do not suit; not a first choice, and not what a spa means by the word peel.

• Non-ablative fractional lasers limited evidence

  The most instructive negative result on this page. After five treatments the skin looked better — and virtually every biopsy still showed actinic keratosis or worse. Clinical improvement without histological clearance is precisely the failure that matters in a precancer, and it is why 'my skin looks smoother' cannot be the endpoint here.

• Dermabrasion limited evidence

  It works, and then it stops working: in a follow-up series nearly everyone was clear at one year, and around half of those followed to five years still were. Largely superseded by treatments with less downtime and better evidence, though the principle — resurface the whole damaged field — survives in ablative lasers.

• Beta carotene and antioxidant supplements limited evidence

  The Australian trial that helped establish daily sunscreen's benefit tested beta carotene supplementation in the same population and found no effect on these lesions. Worth knowing before buying the capsule version of a sun-protection plan.

The supporting-care section above describes principles. During and after field treatment the skin behaves like a compromised barrier, and these routines start from that reality.

• Barrier repair routine
• Sensitive skin routine

Everything on this page traces back to the sources below. Actinic keratosis has a current, methodical US guideline, and the evidence behind the specific claims above — the head-to-head field-treatment trial and the nicotinamide trials — is unusually clean and worth reading directly.