Actinic keratosis: a cross-sectional study of disease characteristics and treatment patterns in Danish dermatology clinics.

Objectives: The incidence of actinic keratosis (AK) is increasing, and several treatment options are available. The aim of this study was to describe clinical characteristics and treatment patterns in patients with AK treated by Danish dermatologists.

Methods: A multicenter, non-interventional, cross-sectional study was conducted. Three dermatology hospital departments and seven private dermatology clinics enrolled eligible AK patients consecutively during one week.

Results: A total of 312 patients were included. Non-melanoma skin cancer (NMSC) was previously reported in 51.0% of patients and currently suspected in 9.4% of AK-affected anatomical regions. Lesions of AK were located primarily on the face (38.6%), scalp (12.8%), and hands (11.2%). Actinic keratosis commonly presented with multiple AK lesions (38.6%) and field cancerization (38.5%). The treatments used most frequently were cryotherapy (57.7%) and photodynamic therapy (PDT) with methyl aminolevulinate (17.1%) and imiquimod (11.2%). The likelihood of receiving cryotherapy was higher for men (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.10-2.47) and increased with age (2.2% per year, 0.4-4.0%). PDT represented the most frequently applied treatment for severe actinic damage and was more likely to be prescribed to women (OR 4.08, 95% CI 2.22-7.47) and young patients (OR 0.97 per year, 95% CI 0.95-0.99). The prevalence of severe actinic damage (17.3% versus 9.6%) and intake of immunosuppressive medication (29.0 versus 2.0) were higher among hospital patients compared with those treated in private practices (P < 0.0001).

Conclusions: The majority of AK patients in Danish dermatology clinics have a history of skin cancer, and NMSC is suspected in almost 10% of AK-affected regions. Cryotherapy is the most frequently used treatment overall, except in instances of severe actinic damage, in which PDT is the first-choice treatment.