Digitally Enhanced Methods for the Diagnosis and Monitoring of Treatment Responses in Actinic Keratoses: A New Avenue in Personalized Skin Care

Simple Summary Actinic keratoses are lesions with a variable potential for malignant transformation, but with a difficult predictability of evolution towards this type of lesions. Non-invasive skin imaging methods represent diagnostic tools that allow a better evaluation of actinic keratoses lesions, as well as the establishment of a diagnosis with greater specificity and sensitivity. This review aims to identify all skin imaging methods that are useful in the diagnosis and monitoring of the treatment of actinic keratoses, as well as to identify those lesions at risk of transforming into squamous cell carcinoma.Abstract Non-melanocytic skin cancers represent an important public health problem due to the increasing incidence and the important local destructive potential. Thus, the early diagnosis and treatment of precancerous lesions (actinic keratoses) is a priority for the dermatologist. In recent years, non-invasive skin imaging methods have seen an important development, moving from simple observational methods used in clinical research, to true diagnostic and treatment methods that make the dermatologist's life easier. Given the frequency of these precancerous lesions, their location on photo-exposed areas, as well as the long treatment periods, with variable, imprecise end-points, the need to use non-invasive imaging devices is increasingly evident to complete the clinical observations in the diagnosis and treatment of these lesions, with the aim of increasing accuracy and decreasing the adverse effects due to long treatment duration. This is the first review that brings together all skin imaging methods (dermoscopy, reflectance confocal microscopy, ultrasonography, dermoscopy-guided high frequency ultrasonography, and optical coherence tomography) used in the evaluation of actinic keratoses and their response to different treatment regimens.