Sensoriality of emollient creams: can sensory experience compromise blinding in trials?

Abstract Background Regular application of emollients, particularly those that enhance the skin’s acid mantle and promote ceramide production, can help restore skin barrier integrity, reduce inflammation and prevent disease flares. These emollients not only protect the skin, but also modulate on the skin microbiome, which has become a cornerstone in disease management. Sensory properties, such as texture, appearance and the sensation of freshness, are critical factors influencing patient perception, treatment adherence and product efficacy. Objectives To test, a controlled study involving 120 participants, the ability of consumers to recognize emollient creams based solely on sensory characteristics to ensure that sensory stimuli from emollients cannot be a source of unblinding in a clinical trial involving topical corticosteroids. Methods We conducted a double-blind quantitative assessment in a controlled environment involving 120 healthy volunteers who were regular users of moisturizing creams, of whom 50% were classified as ‘naïve’ users and 50% as ‘connoisseurs’. The creams under investigation (n = 4) were placed in identical bottles and evaluated in monadic sequence according to a Latin square experimental design. Results There were no significant statistical differences in overall appearance, shine or transparency between the four emollients. Only 6% of consumers recognized Neutraderm, 8% La Roche-Posay, 6% Avene and 4% Uriage (i.e. figures below any recognition by chance). Overall, we report a satisfaction rate of almost 60% for the topicals used (from 45% up to 64%). Conclusions This finding supports the feasibility of conducting blinded clinical trials on the emollients used in this study as sensory cues are unlikely to compromise the blinding.