Topical field treatments for actinic keratoses
Topical field treatments can be considered for patients with multiple or field actinic keratoses, or when cryotherapy is not suitable. Response to topical field treatments is variable; follow-up to review treatment outcome is important.
For mild actinic keratoses, or those in cosmetically sensitive areas, diclofenac 3% gel or tretinoin 0.05% cream can be considered; these treatments are thought to be milder than other optionsDianzani, 2020Dirschka, 2017. Topical field treatment is more commonly achieved with fluorouracil or imiquimod. Use:
1fluorouracil 5% cream topically, once or twice daily for 2 to 4 weeks on the face or 3 to 6 weeks on limbs. For detailed information on correct application, see the product information fluorouracil fluorouracil fluorouracil
OR
1fluorouracil 4% cream topically, once daily for 4 weeks. For detailed information on correct application, see the product information fluorouracil fluorouracil fluorouracil
OR
1imiquimod 5% cream topically, 3 times a week on non-consecutive days for 4 weeks. If any lesions persist, the treatment can be continued for up to 16 weeks. For detailed information on correct application, see the product information. imiquimod imiquimod imiquimod
Fluorouracil cream is the most commonly used topical agent because of its lower cost and comparable efficacy.
The patient should stop topical field treatment once there is a moderate inflammatory reaction. Topical field treatments are expected to cause inflammation that can last up to several weeks—explain this to the patient. Consider the patient’s occupation and social commitments when deciding on the timing of treatment, particularly if cosmetically sensitive areas are affected.
If topical therapy is not effective, consider referral to a specialist for biopsy or specialist treatments. Photodynamic therapy can be considered by specialists as an alternative to fluorouracil and imiquimod topical field treatments. Photodynamic therapy involves application of a photosensitiser to the affected skin, followed by activation with light. Various photosensitisers and light delivery techniques are available. Good technique and patient selection are important for optimal response.
Oral nicotinamide may be considered as a chemopreventive adjunct to sun protection for patients with a history of multiple skin cancers, although further trials are required to determine its efficacyChen, 2015Surjana, 2012 Giacalone, 2021Gilmore, 2018.