Conventional treatment of actinic keratosis: an overview

Nonsurgical procedures are the first-line treatment for actinic keratosis (AK). The choice of therapy is based on AK features and patient characteristics. Numerous randomized clinical trials and open-label studies have provided robust data on the efficacy and tolerability of conventional topical therapies, such as cryotherapy, photodynamic therapy, or treatment with 5-fluorouracil, diclofenac, or imiquimod. Cryotherapy is recommended to treat single AK lesions (lesion-directed therapy), while topical medical therapies are used to treat multiple lesions on an entire sun-damaged area (field therapy) and have the advantage of highlighting and treating both visible and invisible lesions. Combined or sequential therapies have been proposed to improve treatment efficacy, while medication breaks between treatment cycles or lowering drug concentrations is used to increase treatment tolerability/adherence. The use of a field therapy to treat multiple lesions on a large area (the entire face or a balding scalp), followed by a lesion-targeted therapy for a specific recurrent or resistant AK lesion, is becoming an increasingly popular approach. Regarding surgical procedures, curettage with or without electrodessication and dermabrasion are seldom used, while excision is indicated when AK progression to invasive squamous cell carcinoma is clinically suspected. Despite the availability of most such treatments for more than a decade and their common use in clinical practice, there is still a need for long-term follow-up studies to better determine the recurrence rate and for comparative studies to develop a truly patient-tailored therapy.