43498 Podiatry Rev Mar 20/02/2014 15:43 Page 21
The management of dry skin in the elderly Michelle Taylor MInstChP BSc
The skin of the patient can provide a diagnostic indicator for various systematic disorders and provide an insight into their health and wellbeing. The quality of both deep and superficial peripheral tissues, along with any physical changes can also be noted (Lorimer, D. et al 2006). The skin is the largest organ of the body and makes up roughly 15% of the person’s body weight. As a person’s ages, changes within the skin occur making it vulnerable to damage from mild mechanical injury forces, moisture, friction and trauma (International review 2010).
The skin is known as the Integumentary System [Science Links]. The skin is the outer covering of the body and is made up of 2 main layers. The epidermis is the outer layer of skin, while the dermis is the inner layer which lies on a layer of fatty tissue. The epidermis protects the body from injury and parasites, as well as preventing the body from becoming dehydrated. A combination of erectile hairs, sweat glands and capillaries within the skin forms part of the temperature control mechanisms of the body. The skin also acts as both an excretion organ - via secretion of sweat - and a sense organ, as it contains receptors that are sensitive to heat, cold, touch and pain. The layer of fat underneath the dermis acts as a reservoir of food and water for the skin (Concise Medical Dictionary 2002). The epidermis is made up of layers or zones, • The top or outer layer being known as the horny layer – stratum corneum. • Granular (stratum granulosum) layer. • Germative layer. • Pickle cell (stratum spinosum). • Basal layer (stratum basale).
These 5 layers make up the epidermis and cover the dermis and underlying subcutaneous tissue (Watson, R 2005).
The germative layer produces the main cells (keratinocyte) of the epidermis. These cells raise from the basal cell layer through each of the layers of the epidermis – stratum spinosum, gradulosum and lastly the stratum corneum the outer most layers. Once the cells have reached this outer most layer they have gone through a process of differentiation, which has transformed them into dead, flattened, anucleated cells called “coenocytes”, which can take between 28 – 46 days to complete. This outer layer
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Between the epidermis and dermis a dermoepidermal junction forms to help anchor the epidermis and dermis together. The dermis makes finger like folds into the epidermis which are known as dermal papillae. These dermal papillae are complement by protrusions from the epidermis known as rete or epidermal ridges or pegs. Where there is an increase in mechanical stress a stronger attachment is formed between the dermal papillae and rete pegs (Gawkrodger, D.J. et al 2012) (Dawber, R et al 2001). Collagen fibres account for up to 70% of the dermis giving both strength and toughness to the structure. Elastin fibres provide elasticity to the skin; these fibres are loosely arranged in all directions within the dermis (Gawkrodger, D.J. et al 2012).
(Gawkrodger, D.J. et al 2012)
(stratum corneum) is where the barrier function of the skin occurs. Due to the high water content within these cells, it allows the cells to not only keep close to each other but also to form a tight but flexible seal (Bristow, I. 2013)
Cell turgidity is maintained through a natural moisturising process (NMF) – an intercellular humectant – which attracts water to itself. NMF is obtained from a substance called filaggrin, which breaks down into a range of NMF`s – urea, amino acids, pyrolidoncaboxylic acid and latic acid. This process maintains the skins natural acidic PH (around 5.5). Lipids originating from the lamellar bodies in the stratum gradulosum, secrete into the epidermis, acting in a similar way to waterproof mortar between the coenocytes (flattered cells) of the horny layer This chemical and PH balance maintains the thickness of the epidermis (Cork, M.J et al 2009).
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The dermis is made of 2 layers, the papillary and reticular layer. The thin upper papillary layer contains most of the blood and lymphatic vessels, while the reticular layer is not as vascular, it does contain denser collagen and elastic fibres. T – Lymphocytes and mast cells of the immune system are present within the dermis (Dawber, R. et al 2001). Also present within the dermis there are numerous hair follicles and sweat glands (Gawkrodger, D.J. et al 2012).
The paper thin appearance of the skin associated with the elderly is due to an estimated 20% reduction in the thickness of the skin (Haroun, M.T. 2003). Thinning of the dermis sees a reduction in blood vessels, nerve endings and collagen. This causes a decrease in sensation, temperature control, rigidity and moisture retention (Barsnoski, S. et al 2004). A combination of reduced sweat glands and a lack of production of sebum make the skin difficult to keep hydrated leading to dryness and itching (Watkins, J. 2011). The ability to detect temperature changes via the skin makes the elderly prone to the cold and hypothermia. A reduced ability to regenerate, with a less efficient immune system, increases the risk of skin breakdown from even the slightest injury (Voegel, D. 2012). As the skin barrier fails it becomes dry (xerotic), scaly and loses
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