Dry skin

Dry skin is common; as skin loses moisture the surface cracks.

The inherited forms of dry skin are known as 'ichthyosis' (fish-scale skin) - [pictured below left]. There are various kinds of ichthyosis. Dermatologists often call dry skin arising in later life 'xerosis', 'asteatosis' or 'acquired ichthyosis'.

The dry areas may result in dermatitis [pictured below right], ie. the skin becomes red and itchy. This may result in a crazy-paving appearance on the lower legs ('eczema craquelé'), or round patches scattered over the trunk and limbs (a dry form of nummular dermatitis). Sometimes the dry skin is just itchy, without much of a rash (sometimes known as 'winter itch', '7th age itch', or 'senile pruritus').

Ichthyosis	Dermatitis from dry skin

Images Copyright DermNet (NZ)

Causes of dry skin

Factors which contribute to dry and cracked skin include:

• inherited factors
• metabolic factors such as an under-active thyroid gland, or excessive weight loss
• increasing age, resulting in decreased natural lubrication
• cool weather, especially when windy or the humidity is low
• air conditioning, central heating or sitting close to a fire or fan heater
• excessive bathing, showering or swimming, especially in strongly chlorinated hot or cold water
• contact with soap, detergents and solvents
• frictional irritation and chapping.

Treatment of dry skin

An important aspect of treatment is to identify and tackle any contributing factors (see the list of causes above).

• Reduce how often you bath or shower, and use lukewarm water. Showers may be better than baths.
• Replace standard soap with a substitute such as a synthetic detergent cleanser, water-miscible emollient, bath oil, anti-pruritic tar oil, etc.
• Apply an emollient liberally and often, particularly after bathing, and when itchy. The drier the skin, the thicker this should be, especially on the hands.
• Treat eczematous patches with a topical steroid for a 5 to 15 day course. These are prescribed by your doctor and should be only applied to the red and itchy areas.

Long term control

Dry skin is usually a long term and recurring problem, especially in winter. When you notice your skin getting dry, resume your lubricating routine and use a non-soap cleanser. If the itchy dry-skin rash returns, use both the lubricating routine and the prescription steroid cream or ointment.

Original material provided by the New Zealand Dermatological Society Inc. (DermNet NZ), and reviewed by everybody, August 2005.