What is first-line treatment for a single, discrete actinic keratosis?

Cryotherapy is first-line for discrete actinic keratoses — a 3-5 second freeze as a single or double freeze-thaw cycle. It is low-cost, needs no anaesthetic, and doesn't rely on patient adherence to a cream course. Warn patients about swelling, blistering and hypopigmentation, which is more likely in darker skin.

When should I use field therapy instead of cryotherapy for actinic keratosis?

Field therapy (5-fluorouracil, imiquimod, photodynamic therapy, or diclofenac gel) suits high-density actinic keratoses or areas with poorly-defined lesion borders, because it also treats subclinical sun damage that isn't yet visible. It requires good patient adherence and causes a visible inflammatory reaction, so set expectations before starting.

When should I refer actinic keratosis to a dermatologist?

Consider referral for immunosuppressed patients, widespread or severe sun damage, suspected keratinocyte carcinoma (bleeding, ulceration, tenderness, heavy induration, nodularity, or a lesion resistant to treatment), or a younger patient with more actinic keratoses than expected for their age.

Actinic Keratosis Management Pathway

Cryo, cream, curettage, or refer? Select the lesion pattern below for a recommended approach.

📋 Source: Freeman/Mar et al., "Actinic keratosis: an update on management", Medicine Today 2023.
Decision support only, not a clinical directive — patient factors, comorbidities and preference should guide the final choice. Always check current TGA approval and PI for any medication mentioned.

1. Lesion pattern

5-fluorouracil 5% or 4% cream (e.g. Efudix): thin layer once or twice daily for 2–4 weeks, or as tolerated. Strongly recommended by AAD for field therapy. See the patient cream guide for what to expect.

5-FU 0.5% + salicylic acid 10% solution: for lesion or small-field therapy (under 25cm²), once daily for up to 12 weeks. Can be used as a periodic winter treatment in high-risk patients.

Imiquimod 5% cream (e.g. Aldara): TGA-approved for face and scalp only. 3×/week in 4-week cycles, or consecutively for up to 16 weeks, per patient preference.

Photodynamic therapy (PDT): single treatment, reassess at 3 months, retreat only if residual lesions remain. Daylight PDT is less painful and usable year-round with similar efficacy to clinic-based red-light PDT.

Diclofenac 3% gel: lower-strength evidence. Twice daily for 60–90 days. Caution with history of GI bleeding/ulceration; avoid with concurrent oral NSAIDs.

Tirbanibulin 1% ointment: 5-day course. Not yet TGA-approved at time of writing — check current status. Contraindicated in pregnancy/breastfeeding. Higher 1-year recurrence (47%) than 5-FU or imiquimod.

Ingenol mebutate: not recommended — withdrawn, linked to increased skin cancer risk in treated areas.

Use shared decision-making — adherence and tolerance of the local inflammatory reaction affects which field therapy works in practice. All patients should get sun-protection education regardless of treatment chosen.

For immunosuppressed patients: reinforce sun protection, schedule regular skin checks, and consider referral given higher progression risk. Low-dose acitretin has evidence as chemoprevention in this group; nicotinamide evidence is inconclusive.

Cryotherapy hypopigmentation risk is higher in darker or olive skin — factor this into the choice and consent discussion. See the Cryotherapy MBS & Technique Guide for freeze times.