{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T01:20:38Z","timestamp":1776216038677,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T00:00:00Z","timestamp":1701043200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Actinic keratosis (AK), due to its widespread prevalence, as well as the possibility of progression to an invasive form of squamous cell carcinoma, requires treatment regardless of the clinical stage. New imaging techniques, such as in vivo reflectance confocal microscopy (RCM), significantly increase the accuracy of diagnosis and allow noninvasive evaluation of the therapeutic efficacy of the ongoing treatment. Our objective was to evaluate the prevalence of specific (video)dermoscopy and RCM features of pigmented and classical subtypes of AK before and after photodynamic therapy (PDT) treatment. We included patients with facial grade II AKs (25 pigmented, 275 non-pigmented) were included in the study. Skin lesions were evaluated by (video)dermoscopy and RCM at the baseline and three months after PDT. In classic AK, the most frequent dermoscopic findings were fine wavy vessels (96%), scale (92%), microerosions (48%), and \u201cstrawberry\u201d pattern (36%), while pigmented AK was characterized mostly by \u201crhomboidal pattern\u201d (80%), scale (60%), white globules (48%), \u201cjelly sign\u201d, and superficial pigmentation (40%). RCM\u2019s most characteristic classic AK findings were abnormal honeycomb pattern in the spinous layer, epidermal inflammatory infiltrate, and solar elastosis that were present in 96% of lesions. Pigmented AKs presented mostly with dark central areas of parakeratosis (72%), mottled pigmentation (72%), dermal inflammatory infiltrate (64%), solar elastosis (60%), and abnormal honeycomb pattern in the spinous layer (56%). Dermoscopically, PDT resulted in complete disappearance of the \u201crhomboidal pattern\u201d in both classical and pigmented AKs, \u201cstarburst pattern\u201d and \u201cjelly sign\u201d in classical AKs, and inner gray halo, \u201crosette sign\u201d and central crust in pigmented AKs. Three months after one PDT session, RCM evaluation showed mostly solar elastosis in both classical and pigmented AK subtypes, epidermal inflammatory infiltrate in classical AKs, and dermal inflammatory infiltrate in pigmented AKs. New noninvasive imaging techniques such as RCM and (video)dermoscopy can help practitioners better visualize the efficacy of the ongoing PDT treatment in either classical or pigmented AK subtypes.<\/jats:p>","DOI":"10.3390\/cancers15235598","type":"journal-article","created":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T03:35:06Z","timestamp":1701056106000},"page":"5598","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Reflectance Confocal Microscopy and Dermoscopy of Facial Pigmented and Non-Pigmented Actinic Keratosis Features before and after Photodynamic Therapy Treatment"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2329-6863","authenticated-orcid":false,"given":"Ewelina","family":"Mazur","sequence":"first","affiliation":[{"name":"Department of Dermatology, Institute of Medical Sciences, Medical College of Rzeszow University, 35-959 Rzeszow, Poland"},{"name":"Doctoral School, University of Rzeszow, 35-310 Rzeszow, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3268-012X","authenticated-orcid":false,"given":"Dominika","family":"Kwiatkowska","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Institute of Medical Sciences, Medical College of Rzeszow University, 35-959 Rzeszow, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5573-1754","authenticated-orcid":false,"given":"Adam","family":"Reich","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Institute of Medical Sciences, Medical College of Rzeszow University, 35-959 Rzeszow, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1016\/j.ad.2016.05.016","article-title":"Prevalence of actinic keratosis among dermatology outpatients in Spain","volume":"107","author":"Plazas","year":"2016","journal-title":"Actas Dermosifiliogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1111\/jdv.12102","article-title":"Prevalence and risk factors of actinic keratoses in Germany-analysis of multisource data","volume":"28","author":"Schaefer","year":"2014","journal-title":"J. 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