Factors influencing the skin barrier function:

  • The effects of ageing / Elderly skin
  • Neonates
  • pH levels of the skin
  • Dry skin
  • Moisture
  • Moisture Associated Skin Damage (MASD)

The effects of ageing

 Neonates Moisture Dry skin

Elderly skin has fewer sebaceous glands resulting in reduced secretion of natural lipids, increasing the need to moisturise.2,29

Elderly skin develops a flattening of the rete ridges that hold the epidermis and dermis together resulting in the higher incidence of skin tears in the elderly.29

Premature babies have fragile, thinner, more immature skin than full term babies, resulting in higher Trans Epidermal Water Loss.19

The skin of full-term babies contains 10-20 layers of stratum corneum. Premature babies only have 2-3 layers.17

The overall result is that preterm babies are more prone to skin trauma from adhesive dressings and tapes and localised pressure from IV lines and tubing.19

The term ‘moisture-associated skin damage’ (MASD) is used to describe all types of skin damage caused by moisture.21

Damage to the skin caused by moisture has a significant impact, decreasing the skin’s ability to act as a functional protective barrier.21

When the skin becomes dry, the superficial corneocytes on the surface attached to the deeper keratinocytes, pile up and become visible as scaly, rough and flaky skin.15

When skin is dry, the function of the acid mantle is reduced resulting in reduced protection against bacteria. This, together with minor trauma from scratching, increases the risk of skin infection.31

Moisture balance is imperative to wound healing

If exudate is not properly managed the periwound skin may become macerated.38

Macerated skin has a higher pH than normal skin and increases the risk of bacterial and fungal infections, such as Candida albicans. 4,19

It is important that excess exudate is removed from the wound by an absorbent dressing with the ability to contain exudate under pressure.1

MASD - moisture associated skin damage

Chronic wound fluid

Chronic wound exudate is rich in: 1

  • Growth factors that which promote healing
  • Dead white cells, bacteria, high levels of inflammatory mediators and proteases which can disrupt the normal wound healing process

High protease content of chronic wound fluid causes maceration and breaks down of the stratum corneum.19,38

Failure to manage exudate adequately can lead to exposre of the periwound skin to moisture resulting in maceration of the periwound skin.38

Intertriginous dermatitis (ITD)

ITD is an inflammatory dermatosis occurring as a consequence of moisture, friction and bacteria trapped between two skin surfaces.6

In skin folds, there is a risk that sweat can get trapped leading to build-up of moisture and when the skin rubs together it becomes painful due to skin excoriation. 37

This increases the risk of secondary infection by fungi and bacteria and leads to intertrigo.37

Peri-stomal moisture-associated dermatitis

Peri-stomal skin damage occurs when skin is exposed to effluent from an ostomy, resulting in inflammation and erosion.38

Lipases and proteases produced by faecal bacteria break down protein in keratinocytes, contributing to skin breakdown.6

Incontinence Associated Dermatitis

Incontinence Associated Dermatitis (IAD) is a complex mechanism that is not fully understood but involves an interaction between, urine and faeces on the skin, humidity, mechanical irritants and frequent use of soap and water.19

If the skin is exposed to urine, faeces and detergents for a longer time the skin pH becomes more alkaline disturbing the acid mantle and increasing skin damage.19

Diagnosing the cause of skin barrier damage

In the sacral area, even experts have difficulty identifying if skin damage is due to pressure damage or moisture damage.22

An example is patients who are at risk for IAD. They are also at risk for pressure ulcer development, due to impaired tolerance to friction and sheer when IAD is present.6

Stage I pressure ulcers are often mistaken for mild/moderate IAD as both conditions present as erythema of intact skin.6,19