Treatment of actinic keratoses

Actinic keratoses (AKs) are red or brown flat scaly lesions that are rough to touch. They occur when sufficient chronic sun exposure allows for genetically damaged epidermis to exhibit clinical lesions. All of the skin is affected (field change) with the most damaged areas expressed as discrete lesions of variable thickness and scale. AKs can be itchy, scaly, rough, sore or bleed. Shallow ulceration can develop as well as persistent sterile pustulation. An uncertain but small percentage transform into squamous cell carcinoma (SCC). This is more likely to happen in immunocompromised patients, those with a previous SCC, elderly patients and extensive moderate/severe AKs. Not all AKs need treating but they should be identified.

Advice on available treatments, sun protection, and risk of skin cancer and skin self-examination should be given. Since AKs are a marker for all types of skin cancer, the patient should be inspected on the arms, lower legs, chest, upper back, neck and head as a bare minimum examination.

All year round regular sun protection (which may include sunblock) will reduce the frequency of new visible lesions developing and mild lesions will regress.

The vast majority of AKs can be managed in primary care. To properly manage AKs, it is best to separate field change from separate lesions and stratify into mild, moderate and severe cases.


Red flag signs that should prompt referral to secondary care are:

  • Immunosuppressed patients
  • Bowen's disease
  • Painful lesions
  • Cutaneous horns
  • Rapidly growing lesions
  • Deeply ulceration lesions and solitary lesions without convincing evidence of surrounding chronic sun damage
  • Pigmented facial lesions may also be very difficult to tell apart from lentigo maligna

Field change treatment

Areas of treatment should not exceed 5cm x 5cm. Divide into sections for larger fields

Sun-protection and Self-examination advice should be given to all patients

Differential diagnosis: seborrhoeic keratosis; dermatitis; Bowen's and SCC

Mild to Moderate AKs

Ingenol mebutate

  • Face and scalp: One tube of 150 microgram/g gel applied once daily for 3 days
  • Trunk and extremities: One tube of 500 microgram/g gel applied once daily for 2 days

Moderate to Severe AKs

Fluorouracil cream 5%

  • Apply thinly to the affected area once or twice daily; maximum area of skin treated at one time, 500 cm2 (e.g. 23 cm × 23 cm); usual duration of initial therapy 3–4 weeks

Ingenol mebutate

  • Face and scalp: One tube of 150 microgram/g gel applied once daily for 3 days
  • Trunk and extremities: One tube of 500 microgram/g gel applied once daily for 2 days

Methyl-5-aminolevulinate cream (Metvix®) with Photodynamic therapy (PDT)

  • Cream 160mg/g
  • With Photodynamic Therapy. Review response 3 months post treatment. Re-treat or refer if palpable lesions present
  • Available in secondary or intermediate care.
  • For the treatment of AKs, Bowens disease and superficial BCC.
  • Useful in delicate skin at risk of ulceration and poor wound healing or where an alternative treatment would be disfiguring.
  • Also useful for AK induced scalp erosive pustulosis.

Individual AK lesions


Sun-protection and self-examination advice



  • Available in primary, intermediate and secondary care. Two freeze-thaw cycles of 10 seconds. Hyperkeratotic lesions unlikely to respond without debridement. Patient at risk from permanent hypo pigmentation or atrophic scarring.

Fluorouracil with salicylic acid (Actikerall®)

  • Apply once daily for up to 12 weeks; max. area of skin treated at one time, 25 cm2 (e.g. 5 cm x 5 cm)


Curettage and cautery (with pathology)

  • Hyperkeratotic lesions, cutaneous horns and where the index of suspicious of SCC transformation is high.
  • Always send each curetted specimen in a separate histology pot for pathology.
  • Review at 6 weeks post treatment. Re-treat or refer if lesion not resolved

Combination therapy

Combination therapy should be used when the patient presents with both individual AKs and field change, although most topical agents will deal with mild to moderate individual lesions.


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