Homeostasis and epidermal barrier analysis in psoriatic patients: the impact of emollients

Abstract

BACKGROUND: Skin diseases may modify epidermal barrier function. Psoriasis is a chronic multi-systemic inflammatory disease that may affects the epidermal barrier. Emollients are an option as a coadjutant therapy for psoriasis management, but little is known about how epidermal barrier function is modified by moisturizers administration in psoriatic patients. HYPOTHESIS AND OBJECTIVES: The objective of this before-and-after study is to analyse skin homeostasis and epidermal barrier function differences between psoriatic plaque, non-affected skin in psoriatic patients and control skin; also, to evaluate the effect of two types of moisturizers on psoriatic and healthy participants. METHODS: Thirty-one patients with plaque-type psoriasis and thirty-one gender and age-matched healthy controls were enrolled. Temperature, Transepidermal water loss (TEWL), stratum corneum hydration (SCH), pH, elasticity and erythema index were measured using non-invasive tools in the healthy control and involved and uninvolved psoriatic skin before and after the use of two determined moisturizers RESULTS: Healthy controls had lower TEWL, temperature, and higher pH levels than psoriatic patients. SCH levels were found lower in psoriatic plaques than in uninvolved and healthy skin (13,44 vs 30,55 vs 30,90 Arbitrary Units (AU); p<0,001). TEWL was significantly higher in plaques than in psoriatic uninvolved skin (13,23 vs 8,54 g/h/m2; p<0,001)., which was also higher than in control healthy skin (8,54 vs 6,41 g/h/m2; p=0,023). After emollients application on psoriatic plaques, SCH experimented a significant increment after the application of water-based formula (13,44 vs 22,89 AU; p=0,003). However, TEWL showed a decrease of 5,59 g/h/m2 (5,68 SD, p<0,001) after use of Vaseline jelly; and the contrary effect after the water-formula application (increment of 3,60 g/h/m2 (6,86 SD, p=0,006). CONCLUSION: Uninvolved psoriatic skin showed epidermal barrier dysfunction compared to healthy controls; in addition, psoriatic plaques barrier impairment was significantly higher than not-affected skin. Use of emollients may improve epidermal barrier function in psoriatic patients. SCH and TEWL parameters were the most changed after moisturizers application