biostudies-literatureCostello LConsejo Nacional de Ciencia y TecnologíaProcter and GambleBiotechnology and Biological Sciences Research Council620-631https://www.ebi.ac.uk/biostudies/studies/S-EPMC10947487biostudies-literatureUnknown32(5)Skin ageing is an intricate physiological process affected by intrinsic and extrinsic factors. There is a demand to understand how the skin changes with age and photoexposure in individuals with Fitzpatrick skin types I-III due to accelerated photoageing and the risk of cutaneous malignancies. To assess the structural impact of intrinsic and extrinsic ageing, we analysed 14 skin parameters from the photoprotected buttock and photoexposed dorsal forearm of young and ageing females with Fitzpatrick skin types II-III (n = 20) using histomorphic techniques. Whilst the minimum viable epidermis (E_min ) remained constant (Q > 0.05), the maximum viable epidermis (E_max ) was decreased by both age and photoexposure (Q ≤ 0.05), which suggests that differences in epidermal thicknExperimental dermatologyQuantitative morphometric analysis of intrinsic and extrinsic skin ageing in individuals with Fitzpatrick skin types II-III.PMC10947487BB/K019260/1BB/M011186/12019‐000021‐01‐EXTF‐00262Simpson AMaatta ATasseff RIsfort RPrzyborski SDicolandrea TWei XMarkiewicz EGoncalves KBascom CCKarakesisoglou IDe Los Santos Gomez PRitchie PMaltman VCostello LfalseQuantitative morphometric analysis of intrinsic and extrinsic skin ageing in individuals with Fitzpatrick skin types II-III.Skin ageing is an intricate physiological process affected by intrinsic and extrinsic factors. There is a demand to understand how the skin changes with age and photoexposure in individuals with Fitzpatrick skin types I-III due to accelerated photoageing and the risk of cutaneous malignancies. To assess the structural impact of intrinsic and extrinsic ageing, we analysed 14 skin parameters from the photoprotected buttock and photoexposed dorsal forearm of young and ageing females with Fitzpatrick skin types II-III (n = 20) using histomorphic techniques. Whilst the minimum viable epidermis (E_min ) remained constant (Q > 0.05), the maximum viable epidermis (E_max ) was decreased by both age and photoexposure (Q ≤ 0.05), which suggests that differences in epidermal thickn2023-01-01T00:00:00Z2023 May2025-04-20T02:48:16.68Z2025-02-19T03:09:44.443ZS-EPMC109474873669518510.1111/exd.14754