What is dry skin?
‘Dry’ is used to describe a skin type that produces less sebum than normal skin. As a result of the lack of sebum, dry skin lacks the lipids that it needs to retain moisture and build a protective shield against external influences. This leads to an impaired barrier function. Dry skin (Xerosis) exists in varying degrees of severity and in different forms that are not always clearly distinguishable.
Significantly more women suffer from dry skin than men and all skin gets dryer as it ages. Problems related to dry skin are a common complaint and account for 40% of visits to dermatologists.
The causes of dry skin
Skin moisture depends on supply of water in the deeper skin layers and on perspiration.
Skin is constantly loosing water via:
- Perspiration: active water loss from the glands caused by heat, stress and activity.
- Trans-epidermal water loss (TEWL): the natural, passive way in which skin diffuses about half a litre of water a day from the deeper skin layers.
Dry skin is caused by a lack of:
- Natural moisturising factors (NMFs) - especially urea, amino acids and lactic acid – that help to bind in water.
- Epidermal lipids such as ceramides, fatty acids and cholesterol which are needed for a healthy skin barrier function.
As a result, the skin’s barrier function can become compromised.
How to identify different degrees of dry skin
Dry skin ranges from skin that is a little bit drier than normal, through very dry skin to extremely dry skin. The differences can normally be distinguished by:
Dry skin
Mildly dry skin can feel tight, brittle and rough and look dull. Skin elasticity is also low.
Very dry skin
If the dryness is not treated, skin may develop:
- mild scaling or flakiness in patches
- a rough and blotchy appearance (sometimes it appears to be prematurely aged)
- a feeling of tightness
- possible itchiness
- It is also more sensitive to irritation, redness and the risk of infection. Find out more in dry skin.
Extremely dry skin
Certain areas of the body – particularly hands, feet, elbows and knees – are prone to:
- roughness
- chapping with a tendency to form rhagades (cracks)
- calluses
- scaling
- frequent itchiness
Extremely dry skin is most commonly found on the elderly or on severely dehydrated hands. Read more in rough and cracked body skin.
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