2.2 SKIN CLEANSING For both children and adults, bathing to cleanse the skin is a hygienic necessity. The goal of hygiene is the preservation of skin health. Cleansing is essential to remove: potentially pathogenic bacteria, such as those from faeces; bodily secretions, such as faeces and saliva that contain enzymes (lipases and proteases) that breakdown the skin barrier; foods, including milk that can disturb skin homeostasis and peanuts that can cause sensitization; and other chemical irritants in the environment.1 However there is a balance to be made between cleansing the skin and preservation of its homeostatic properties such as skin barrier function and integrity.5 For instance some soaps and cleansers used to clean the skin that contain harsh detergents, such as sodium lauryl sulfate (SLS), increase skin surface pH, reduce skin hydration and alter skin barrier function.6 Nevertheless cleansers are important. Washing with water alone is ineffective at removing fat-soluble substances from skin.7 The surfactants in cleansers are required to remove these potential fat-soluble irritants. Moreover, washing with tap water alone leads to the extraction of water-soluble metabolites from the skin, including NMF, and causes mild irritation and increased skin dryness. Washing with hard water, as opposed to soft water, in particular is consistently reported to increase the risk of developing AD. A balance is therefore required between effective cleansing and the need for cleansers that are kind to the skin.8 There is now a wide range of detergents and detergent complexes available for the use in cleansing with a spectrum of effects on the skin from harsh irritant effects, such as those caused by SLS, to very mild effects comparable to washing with water alone.