Oedema of any kind predisposes the skin to dryness as the skin becomes stretched and undernourished with reduced oil secretion. If prolonged stasis of tissue fluid occurs, the area of oedema becomes transformed into inelastic, fibrotic tissue with thickened skin in the epidermal layer. The skin loses its first-line immunity barrier to bacteria and any penetration of the skin can lead to infection and a worsening of the oedema (Nowicki and Siviour, 2013).
Where there is a risk of lymphoedema following treatment for cancer, or a risk of oedema due to reduced mobility, obesity, or venous disease, diligent daily care of the skin can maintain its integrity and reduce the risk of infection. The term ‘skin care’ refers to skin cleansing, drying and moisturising with the aim of retaining the barrier function of the skin (Moffatt, 2006).
The physiology of the skin
The skin is the largest organ of the body and comprises three layers (Figure 1):
Healthy skin
The appearance of skin can be influenced by environmental, hereditary and internal factors. Healthy skin has an even colour, a smooth supple texture with no breaks, cracks or tears and is warm to the touch without greasiness or dryness (Andrews, 2013). Dougherty and Lister (2015) pointed out that the skin's integrity, continuity and cleanliness are essential to maintain its physiological functions and Penzer and Finch (2001) defined skin health as when the skin fulfils all of its functions and quality of life is not adversely affected.
With increasing age, the skin undergoes natural changes. Ridges in the epidermis begin to flatten and cell turnover slows. The skin becomes drier and less elastic, with an increased risk of tissue breakdown and infection following trauma or injury (Cowdell et al, 2014).
Influence of oedema on the skin
Oedema or lymphoedema occur when there is stasis of protein-rich fluid in body tissues, which causes swelling. In the early stages, the swelling may be soft and easily pitted with thumb pressure but, with time, a chronic inflammation is triggered, and the area of swelling becomes transformed. The skin hardens, becoming dry and undernourished as oil secretion by the sebaceous glands is reduced (Nowicki and Siviour, 2013). As the skin becomes stretched and dry, it is more susceptible to cracks, tears and trauma, which reduce the first-line defence of the body against infection.
Skin cleansing
Regarded as a fundamental value in society, skin cleansing is also a personal act involving individual requirements and standards, which can be influenced by peer groups and family influences (Dougherty and Lister, 2015). Cleansing of the skin is used as an essential part of religious ceremonies and beliefs in addition to the removal of dirt and dust. Cleansing is also used to enhance skin health and appearance and to assist in various approaches to relaxation therapy (Mukhopadhyay, 2011). The frequency and type of skin cleansing can therefore vary considerably between individuals and any required change can be difficult to implement.
Traditionally involving the use of soap and water, cleansing reduces contaminants, pathogenic organisms and excess sebum while assisting with natural skin exfoliation (Walters et al, 2012). Soaps with a high alkaline pH are now known to be harsh on the skin (Lichterfeld et al, 2015) leaving the skin dry and susceptible to infection as the natural acidic pH of the skin is stripped away. It is therefore recommended that abrasive and scented soaps are avoided (Nowicki and Siviour, 2013). Multiple skin-cleansing products are available, but the choice of skin cleanser should ensure that the natural skin oils are not removed so that the integrity of the skin barrier is respected (Walters et al, 2012). A skin cleanser should therefore have a neutral pH and be used daily (or more frequently if necessary), ensuring that all areas of the body, and particularly areas where oedema is present, are washed carefully to remove dead skin cells, dirt and excess sebum.
Lichterfeld et al (2015) described ‘dry’ and ‘humid’ skin areas, which require different considerations in daily care. ‘Dry skin’ areas include surfaces directly exposed to air or clothing such as the face, back and limbs, which require daily cleansing with a skin cleanser and warm water. ‘Humid skin’ areas include areas with natural skin folds such as the axilla, groin and under the breasts. Once cleansed, these areas require more attention to drying and they may require more frequent cleansing than ‘dry skin’ areas.
Skin drying
Drying the skin after cleansing reduces the risk of skin excoriation and colonisation of bacteria on the skin leading to infection (Snelling et al, 2011). Leaving the skin wet can also lead to damage through possible friction of damp skin and resulting skin cooling (Penzer and Ersser, 2010). Andrews (2013) suggested that just gently patting fragile skin after cleansing can leave it wet and prone to maceration. However, as rubbing the skin can damage the epidermis, Ersser et al (2005) recommended the less abrasive action of patting or gently rubbing the skin during drying and Ronda and Falce (2002) suggested that a soft cloth should be used.
When oedema is present, careful attention should be paid to ensure that any skin folds or creases are dried carefully. The areas between the toes should receive particular attention to reduce the risk of fungal infections developing.
Skin moisturising
For patients with, or at risk of oedema, moisturising of the skin after cleansing and drying is an indispensable part of skin care. Moisturisers assist in replacing the lipid film barrier on the skin that has been disturbed by washing and prevent stretched, oedematous skin from losing water (Nowicki and Siviour, 2013). Areas of dry, flaky or cracked skin indicate that the skin integrity has become damaged and the risk of infection increases because of the associated reduced immunity of the limb. Moisturising promotes skin integrity, making it more supple and less likely to become dry or cracked.
An emollient, which covers the skin with a protective film to lock in the moisture, is preferable to cosmetic moisturisers with added perfume or lanolin, which can irritate or dry the skin further. Emollients are available as soap substitutes, lotions, creams and ointments with increasing degrees of greasiness created by the oil content of the formulation (Table 1). The choice of emollient depends on the condition of the skin, its hydration, known sensitivities and patient preference (Moffatt, 2006).
| Type of emollient | Use |
|---|---|
| Soap substitutes | As an alternative to soap or other skin cleansers to improve the skin. They do not lather well like other skin cleansers. Should be used with caution as the skin can become slippery following use (NHS website, 2017) |
| Lotions | Light formulation that spreads easily on the skin. Used as a daily emollient for healthy skin |
| Creams | A thicker formulation, with higher oil content than lotions, which is absorbed quickly and is useful for mild/moderate dry skin |
| Ointments | The greasiest formulation, which is used for moderate to severe dry skin. Can be useful as a night-time emollient with a cream used during the day |
Emollients should be applied to the skin smoothly and gently following the direction of the hair growth, rather than using a rubbing action on the skin. This avoids the emollient clogging the hair follicles leading to inflammation (Moffatt, 2006). Some emollients are paraffin based and present a fire hazard if they are used liberally and the skin is not cleansed between applications (NHS, 2017).
Conclusion
Care of skin that is oedematous, or at risk of the development of oedema, is essential if skin health is to be promoted and infection avoided. The three components of skin care—cleansing, drying and moisturising—should be applied daily and are all as important as each other.
A good knowledge of the appropriate emollient to use according to the condition of the skin ensures that dryness can be avoided and the skin remains intact.