2 BACKGROUND 2.1 SKIN DEVELOPMENT FROM BIRTH The skin visually reaches maturity anywhere between 30 and 37 weeks of gestational age, yet neonatal and infant skin exhibits a 'sensitive' nature.1 To emphasise this, 78% of participants in one study reported a 'rash' in the first month of their newborns life.2 Its now clear that this sensitivity is related to the functioning of the skin barrier, formed by the skins uppermost layer, the stratum corneum. It takes more than 12 months following birth before the stratum corneum reaches structural maturity at a microscopic level.3 This is reflected by the reduced function of the skin barrier during this time, indicated by elevated transepidermal water loss (TEWL).4 The reduced skin barrier function exhibited during the months following birth increases the risk of irritant and allergen penetration through the skin and consequently the development of dermatological conditions.