212 Prevalence and risk factors of actinic keratosis: Results from the rotterdam study

Abstract

Actinic keratoses (AKs) are pre-malignant skin lesions that occur secondary to extended ultraviolet radiation (UVR) exposure. Limited population-based studies are available to analyze the risk factors, severity and natural course of AK. The aim of this study was to calculate the prevalence of AK and investigate its risk factors and progression. Participants from the Rotterdam Study (RS), an ongoing prospective cohort study, who underwent full body skin examination (FBSE) were included. Univariable and multivariable multinomial logistic regression analyses were performed to study associations between selected risk factors and the number of clinically diagnosed AK lesions. A subset of participants underwent two FBSEs approximately 4 years apart for longitudinal assessment. Of the 8,239 included participants, 1,731 (21.1%) had at least one AK lesion, with the majority having 1-3 AKs (54.4 %). Male gender, older age, lighter hair color, Glogau scale, baldness, and a high tendency to develop sunburn were all significantly associated with AK, with the strongest associations detected for participants with ≥10 AKs. Light eye color was associated with severe AK, but not with mild to moderate AK. Current tobacco smokers had lower odds of mild and severe AK when compared to former and never smokers. 1,547 (18.8%) participants underwent two FBSEs. Of this group, 49% did not develop AK, 15.8% had an increase in AK number, 21.7% had a decrease in AK and 13.4% had approximately the same number. In this large-scale population-based study, we demonstrated that higher age, male gender, lighter hair color, baldness, and high Glogau scale score were associated with higher odds of AK. This effect was most prominent for subjects with severe AK. Conversely, smoking showed an inverse relationship with AK, which suggests there is a protective element that reduces the odds of cutaneous pre-malignancy. Over time, AK lesions are more likely to decrease in number rather than increase or remain unchanged.