P16 Effect of moisturisers on allergen-induced inflammation and skin barrier

Abstract

INTRODUCTION: Recent evidence suggests that moisturisers are not beneficial in preventing development of atopic dermatitis (AD) in infants but can increase risk of allergic sensitisation. Given that emollient vehicles can modify the delivery of 'actives' into the skin it is important to examine their effects on epicutaneous sensitization to environmental allergens. OBJECTIVES: To determine the effects of regularly using emollients on cutaneous reactions to house dust mite allergen. MATERIALS AND METHODS: Observer-blind study in 40 adults with house dust mite sensitisation. Participants underwent 4 weeks of treatment with olive oil OO, coconut oil CO and a basic emollient cream EC applied on 3 different areas of both forearms with a fourth area left as a no-treatment control (NTC). Skin barrier integrity was assessed with tape-stripping trans-epidermal water loss (TEWL) and atopy patch tests (APT) were performed. RESULTS: Skin barrier integrity was reduced by all three treatments relative to NTC as indicated by elevated TEWL (OO 30.68 ± 16.08, CO 30.72 ± 15.60 and EC 31.99 ± 16.92 compared to NTC 26.15 ± 13.58 g/m2/h; P = 0.0067). The strongest APT reactions (graded 0-4) were seen following pre-treatment with EC(2.28 ± 1.03) when compared to the NTC (1.70 ± 0.90, P = 0.0147), followed by OO (2.00 ± 1.032), then CO (1.93 ± 0.84). CONCLUSION: Some moisturisers decrease skin barrier integrity and increase reactions to allergens coming in contact with the skin. Further studies are required to better understand the mechanisms of this effect and the role of moisturiser use in the broader development of atopic diseases.