INTRODUCTION
Dry skin is a pervasive and continuing dermatologic concern. It occurs as a sequela to various chronic disease conditions, such as atopic dermatitis and psoriasis.1–3 However, dry skin is also frequently observed in otherwise normal skin and can result from a variety of factors in the general population including weather, chemicals, age, and photodamage.4–6 Depending on its location and severity, dry skin can be unsightly, uncomfortable, and a source of embarrassment.1,3,7 Prall et al. reported that about 60% of female consumers have recurrent or continuous skin dryness, and that an even higher percentage are motivated to initiate some type of preventative therapy for dry skin.8Moisturizers play a key role in dry skin management. They are part of evidence-based care for certain disease conditions and are among the non-prescription products most frequently recommended by dermatologists.9,10 They are also popular among consumers.11 Yet despite their popularity, the term ‘moisturizer’ is vague. The Oxford Online Dictionary definition is simply, “A cosmetic preparation used to prevent dryness in the skin.”12 This is certainly true; however, moisturizer technology is much more complex. Moisturizers available in the marketplace generally fall into one of four broad classes: emollient-dominant, humectant-based, occlusive, and therapeutic.13 These classes differ in terms of their ingredients, mechanism(s) of action, and the level of dry skin relief they provide.Health care provider and consumer interest is growing in cosmetic products that are based on ‘natural’ rather than chemically-derived ingredients, although some are skeptical of natural products’ abilities to deliver benefits comparable to their non-natural counterparts.14–17 A number of moisturizers that contain natural ingredients are now in the market, although not all are based solely on natural ingredients.Colloidal oatmeal enjoys a long history of use as a skin benefit agent and is recognized as a skin protectant active ingredient,18 so it is not surprising that it is found in commercial moisturizer formulations. Such formulations are reported to improve moderate to severe dry skin, relieve dry skin-related itch, and benefit conditions such as atopic dermatitis.2,19–22