White : Diseases of the Skin

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Gary M. White & Neil H. Cox

Diseases of the Skin

3	Topical Therapy

EMOLLIENTS

The use of emollients is widespread throughout the industrialized world. Additives are common and may include botanicals (e.g. kiwifruit and apple), proteins (collagen), exfoliants (e.g. glycolic acid), sunscreens, or other potentially active agents (e.g. retinol). Ironically, however, the science of emolliating, hydrating, and exfoliating the skin is just in its infancy. What does the skin really need? Does the 30-year-old woman with no apparent skin disease need to apply a lotion to her legs? Does applying a moisturizer (without sunscreen) to the face in early adulthood prevent the development of sone lines and wrinkles later in life? (Note also that the sun protection factor in commercial moisturizers is often too low, and applied too thinly, to really make much difference to long-term solar damage.) Further research is warranted.

What is clear is that emollients are critically important in treating certain diseases, most notably the eczemas. In eczema, the barrier function of the skin is damaged and the water content reduced. Hydrating the skin with a shower or bath followed immediately by the application of a cream or ointment (no lotions please) locks in the moisture and helps repair the barrier (Fig.3.1). Patients feel better and the skin improves. Similarly, emollients will help to reduce scaling in numerous other dermatoses, such as psoriasis. Research is ongoing to determine the best composition of emollients to restore skin function, but at present the ‘best' emollient is dictated by patient preference. This may vary according to factors such as degree of dryness, body site (e.g. face versus palms), time of day, work or social commitments, etc.—most patients therefore benefit from trying out and having available a range of agents.

What is vital, where an emollient is appropriate, is that it is used often enough and in adequate amounts to be useful. In children with eczema, for example, it is important to stress that emollients can be applied liberally and often, that they are not potentially harmful steroids, and that they will reduce itch from dry skin. Conversely, it is important that patients do not use steroid preparations for the emollient effect of their base; these should be reserved for inflamed skin. For an adult applying an emollient to all areas several times each day, at least 500 g/week is likely to be required.

In acute but non-infected exacerbations of eczema, application of emollients under damp tubular dressings (wet wraps) can be effective in some children. Particularly aimed at atopic dermatitis, in which staphylococcal infection is common, some emollients for direct application or for use in the bath are manufactured in plain versions or in versions with added antiseptic agents (e.g. benzalkonium chloride, triclosan).

Figure. 3.1 Xerosis. An emollient is necessary to reduce the scaling. A thick cream or ointment is best. Lotions contain too much water and are less effective; they can even have a drying effect.

PRACTICE POINTS

•	The ‘best' emollient is the one the patient prefers.
•	The degree of dryness, body site, time of day, and work or social commitments may all influence which emollient is most suitable.
•	It is vital that emollients are used often enough and in adequate amounts to be useful.
•	It is important that patients do not use steroid preparations for the emollient effect of their base; these should be reserved for inflamed skin.
•	Utilizing a trained dermatology nurse to explain correct use of emollients, topical steroids, and dressings is extremely valuable for patients and their parents.