Actinic keratoses (AKs or solar keratoses) are keratotic macules, papules, or plaques resulting from the intraepidermal proliferation of atypical keratinocytes in response to prolonged exposure to ultraviolet radiation. AKs represent early lesions on a continuum with squamous cell carcinoma (SCC) and occasionally progress to SCC .
Although most AKs do not progress to SCC, AKs are a concern because the majority of cutaneous SCCs arise from pre-existing AKs, and AKs that will progress to SCC cannot be distinguished from AKs that will spontaneously resolve or persist [2,3]. Because of these factors, most clinicians routinely treat AKs . Improvement in associated symptoms and cosmetic appearance can be additional benefits of treatment.
The treatment of AKs will be reviewed here. The epidemiology, clinical manifestations, and diagnosis of AKs are discussed separately. (See "Epidemiology, natural history, and diagnosis of actinic keratosis".)
Overview — Treatment options for actinic keratosis (AK) include destructive therapies (eg, surgery, cryotherapy, dermabrasion), topical medications (eg, 5-fluorouracil [5-FU], imiquimod, ingenol mebutate, diclofenac), chemical peels (eg, trichloroacetic acid), and photodynamic therapy (PDT). In general, lesion-directed treatments, such as cryotherapy and surgical procedures, are the primary approach for isolated lesions . Field-directed therapies, such as topical 5-FU, imiquimod, ingenol mebutate, and diclofenac, are particularly useful for treating areas with multiple AKs. Evidence for efficacy of these therapies is derived from multiple randomized trials and systematic reviews [5-9].
One systematic review and meta-analysis of 83 randomized trials evaluating 24 treatments in over 10,000 patients found sufficient evidence to conclude that the following field-directed therapies are superior to placebo for complete clearance of lesions in the treated field in patients with AKs: 3% diclofenac in 2.5% hyaluronic acid (relative risk [RR] 2.46, 95% CI 1.66-3.66), 0.5% 5-FU (RR 8.66, 95% CI 3.67-21.44), 5% imiquimod (RR 7.70, 95% CI 4.63-12.79), and 0.025% to 0.05% ingenol mebutate (RR 4.50, 95% CI 2.61-7.74) .