Promoting skin hydration

The principles of improving skin hydration are twofold: firstly the need to promote the retention of moisture (and prevent dehydration) and secondly to support the process of adding water to the skin structure. Emollient therapy is a key technique for achieving both approaches by reducing water loss by moisturisation (occlusive effect), promoting water retention and helping water to penetrate directly into the skin, as in the application of creams. Emollient therapy is examined in detail in Emollients and in a best practice review document (Ersser et al., 2007). Even in situations and countries where pharmaceutical emollients are scarce, the effect of safe oils on the skin barrier can be effective (Darmstadt et al., 2002).

Details have been given on washing and drying practices to prevent or minimise water loss from the skin. In summary this includes minimising soap use and considering the use of soap substitutes, avoiding very hot water which enhances evaporation and removes natural skin oils such as sebum, sealing the skin with emollients after soaking, drying to minimise trauma to the skin barrier. Occlusive techniques are the other main techniques that enhance the hydration of the skin and minimise trauma to the skin barrier related to scratching.

Wrapping or bandaging techniques involve a process of occluding the skin to promote skin hydration and skin protection. These techniques may be wet or dry, depending on the relative need for hydration and skin protection, respectively. Hydration is achieved by the application of liberal quantities of emollients under the wrapping, which may be a bandage or cotton clothing. Occlusion increases emollient absorption. Wraps can be very helpful for parents of children with eczema who can be resistant to treatment in order to improve the quality of life and sleep (Goodyear and Harper, 2002). This requires nursing support to ensure parents and the child are need to be taught to prepare them apply the wraps suitably, maintain effectiveness and to minimise any adverse effects. Box 4.1 outlines the principles of wrapping techniques; these apply to both adults and children requiring wrapping.

Box 4.1 Principles of wrapping techniques Helps to interrupt the scratch – itch cycle May reduce topical steroid use – wet garments can help aid penetration of topical treatment Acts as a mechanical barrier preventing further damage to the skin Cools and soothes the skin as water evaporates Prevents emollients being wiped off and protects clothing Maintains hydration Reduces inflammation and allergen load

There are various elements of the basic wet wrapping technique; the following describes some of the core elements which may be adapted according to the need. Two layers of wrapping are used – tubular bandages, ordinary soft cotton clothing or designed commercial garments such as Tubifast. A warm damp inner wrapping layer (produced using comfortably hot water) is placed over skin onto which an emollient and possibly a topical treatment (e.g. steroid) has been applied. Keep tight fitting to prevent fast cooling. The outer dry layer is placed over the wet layer. The frequency of application will depend if the condition is severe or not, if so the parents can wrap each day and night, then once under control apply approximately thrice per week. Overnight use is particularly useful with the utilisation of existing night clothing and the opportunity to ameliorate night-time scratching. Wet wraps can be used for children from 3 months of age.

Dry wraps – A single dry layer is applied over an emollient to aid the occlusive and protective effect. As with wet wrapping, this can be applied to the badly affected areas with either the tubular bandage or the Tubifast garments (e.g. vest, leggings or socks). The garments stretch easily and are more comfortable to wear; they are washable/reusable.

Wraps can normally be used for children from 3 months of age. These principles equally apply to adults requiring wrapping, due to either the need for hydration or to alleviate the effects of damaging scratching behaviour. This process helps to disrupt the scratch–itch cycle, in which scratching aggravates the pruritic experience and thereby may lead to further damage in a cyclic manner.

Medicated paste bandages may also be used under medical supervision. These are used to treat conditions such as eczema that affect the limbs and vary according to their constituent medication, including substances such as zinc oxide, ichthammol and coal tar (both of which alleviate pruritus). As well as acting as a barrier to prevent damage from scratching they can have a cooling and soothing effect on pruritic skin, as well aiding the penetration and effectiveness of topical medications, as with other forms of occlusion. Guidance on how to apply paste bandages has been developed by the BDNG (British Dermatological Nursing Group, 2008). Application should be preceded by bathing and use of a soap substitute and the application of the topical agent. The bandages are applied from the base of the limb, i.e. starting from the wrist or the ankle upwards. There are two methods illustrated in the BDNG ‘how to article’. (1) Cut and overlap method: The limb is then bandaged around the limb through one and half turns creating an overlap by half the width of the bandage each time – it is then cut; this process is repeated as the limb is ascended. (2) The second ‘pleating method’ involves wrapping the bandage around the limb and then folding back or pleating upon itself and then applying in the reverse direction, also overlapping by half the width of the bandage, avoiding pleats near bony prominences. Bandages are covered with a further outer cotton tubular or self-adhesive bandage which prevents staining of clothes and slippage. The final process involves checking that the bandage is not too tight and so the fingers and toes are moveable and perfused normally.

Caution is needed when using wraps, which must be intimated to the patients or their carers. Careful parental teaching is therefore needed, which can be initially time consuming. Occlusion can intensify the activity of active topical treatments such as steroids – always use the lowest strength required to bring condition under control. It is important not to use wet wraps if the skin is infected; as such there is a need to monitor the skin – pulling back the bandages to ensure skin has not got worse. Avoiding the use of occlusion is necessary since – the warmth and moisture favour the build up of microorganisms. Application should also be avoided if the child is unwell. It is advised not to cut holes for fingers or toes too small, as this can lead to swelling in these areas if tight. Useful guidance on wet wrapping is provided by Goodyear et al. (1991), whilst evidence for the efficacy and safety is usefully summarised by Devillers and Oranje (2006), although further research evaluation of these techniques and their optimal usage is still required.