Tretinoin (0.05% cream vs. 5% peel) for photoaging and field cancerization of the forearms: randomized, evaluator-blinded, clinical trial.

BACKGROUND: Topical tretinoin cream is the gold standard treatment for skin ageing, particularly photoaging. The purpose of tretinoin peel was to obtain similar results, but in a shorter time, however, there have been few controlled trials on its effectiveness. OBJECTIVE: To compare efficacy and safety of tretinoin 0.05% cream and 5% as a peeling agent on photoaging and field cancerization of the forearms. METHODS: Clinical trial with therapeutic intervention, prospective, randomized (computer-generated randomization list), parallel, comparative (intrasubject) and evaluator-blinded (except for histology and immunohistochemistry), including 24 women (48 forearms) aged over 60 years who have not undergone hormone replacement and categorized as Fitzpatrick skin phototype II or III. The forearms of the participants were randomized for treatment with 0.05% tretinoin cream three nights a week, or 5% tretinoin peel every 2 weeks. The opinion of the participant, severity of photoaging, corneometry, profilometry, high-frequency ultrasound, histology (haematoxylin-eosin and Verhoeff stainings) and immunohistochemistry (p53, bcl-2, Ki67 and collagen I) were assessed. RESULTS: One participant dropped out. The mean photoaging score reduced 20% and the mean actinic keratosis (AK) count reduced 60% with no difference between treatments. Three efficacy parameters showed opposite effects between the tretinoin treatments (P < 0.05%): (i) thickness of the corneal layer decreased with 0.05% tretinoin and increased by 5%; (ii) dermis echogenicity increased by 0.05% and decreased by 5% and (iii) Ki67 expression increased by 0.05% and decreased by 5%. There was good tolerability for both regimens. CONCLUSION: Tretinoin as a cream 0.05% or peeling (5%) is safe and effective for the treatment of moderate photoaging and forearm field cancerization. The cream was superior in improving ultrasonographic parameters of ageing. Peeling was shown a superior performance in the stabilization of field cancerization.

Forearm skin aging: characterization by instrumental measurements.

BACKGROUND: The intrinsic ageing and photoaged skin present biomechanical and morphological differences, which are reflected in the appearance of roughness, superficial and deep wrinkles, atrophy, reduced elasticity, hypo- and hyperpigmentation and actinic keratosis. OBJECTIVE: To evaluate and compare the characteristics of the flexor (with a predominance of intrinsic ageing) and extensor (chronically exposed to sunlight and other environmental factors, with a predominance of photoageing) skin surfaces of the forearms. METHODS: Interventional, prospective, diagnostic study, including 23 females, aged over 60 years. The extensor and flexor faces of forearms were compared in relation to clinical parameters and non-invasive instrumental measurements, such as skin surface, elasticity, hydration as well as dermal thickness and echogenicity. RESULTS: Regarding the water content of the stratum corneum, the flexor face presented an average value higher than the extensor face. The average of measures obtained through images of high-frequency ultrasound demonstrated greater echogenicity of flexor face compared to the extensor face. The measurements of the skin surface showed significant differences between the faces. The roughness and scaliness were lower in the flexor face. Regarding the depth of wrinkles, there was no significant difference between the faces. The average of the measurements was slightly higher in the flexor face, which demonstrated that wrinkles are present in the intrinsic ageing and photoageing. The presence of elastosis and the reduction in elasticity in the clinical aspect of the photoaged face of forearms were according to the results of the non-invasive measurements. CONCLUSION: Meaningful differences in the biophysical characteristics of the extensor and flexor faces of the forearms were detected. Because the non-invasive instrumental measurements correlated with clinical findings, they may represent useful tools to assess efficacy and safety of skin ageing treatments in clinical research.