Clinical implications of skincare: lessons from placebo-controlled dermatology trials.

Over the past decade, nonprescription skincare has gained significant attention. However, evidence supporting many skincare trends often lacks the rigorous testing seen in randomized controlled trials (RCTs) for prescribed medications. Vehicle arms in RCTs, which test nonmedicated treatments, provide insights that support the advocacy of basic skincare practices. This narrative literature review explores the lessons drawn from vehicle arms of RCTs in the management of conditions like acne vulgaris, actinic keratoses, melasma, postinflammatory hyperpigmentation and rosacea. A literature search was performed on MEDLINE and Embase to identify RCTs involving vehicle arms for the dermatological conditions. Data on outcomes, study design and sample size were extracted and analysed. Basic skincare practices such as cleansing, moisturizing and sun protection have consistently demonstrated meaningful improvements in dermatological outcomes, even without active treatments. Vehicle arms often achieve a substantial proportion of the efficacy seen in active treatments, frequently exceeding half of the efficacy seen in active treatments, emphasizing the potential of simple skincare regimens. For acne vulgaris, two identical international phase III RCTs (involving 2817 participants) demonstrated up to 25.7% improvement in facial acne severity and 51.2% reduction in inflammatory lesions with vehicle treatment. In actinic keratoses, an RCT (