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The Cause of Eczema: What You Weren't Told

Cork MJ. The importance of skin barrier function. Journal of Dermatological Treatment (1997) 8;S7-S13 [email protected]

What Causes Eczema?

No one really knows what causes eczema. However, we do know that people with eczema have skin that is different.

Normal skin pretty much takes care of itself, never really causing us too much trouble. It's the largest organ of your body, flexible, relatively waterproof, keeps you warm or cool by regulating body temperature, and protects you from tiny organisms and infections.

Skin affected by eczema is often dry and cracked, the protective outer layer of skin damaged. As a result, skin affected by eczema loses a lot of water, which interferes with the natural healing process.

The role of the skin barrier with regard to the Cause of Eczema

The skin barrier  appears to play a significant role in how effectively the skin functions, and why certain people get eczema while others do not.  In healthy skin with a resilient skin barrier, allergens cannot penetrate deeper into the skin.  Instead, bacteria and irritants are prevented from entering; the barrier also helps to protect proper levels of hydration in the skin.  Research into the skin barrier has shown that there is a genetic predisposition to a weakened, defective skin barrier.  This allows allergens to penetrate the deeper layers of the skin.

In addition, the defective skin barrier allows for increased interaction with environmental factors such as soap and detergent, house dust mites, hard water, infection and some topical medications and cosmetic products.  This can result in a worsening of eczema symptoms, and a further breakdown of the skin barrier.

Eczema and the immune system

Our immune system is very complex, and it works very hard to protect us. Once the white blood cells of our immune system are set into action, they release substances that cause inflammation. This inflammation causes redness to appear, as well as releasing other substances that can cause itching. Some researchers believe that people who have eczema also have a reduced threshold for the itch sensation. So, once your skin gets itchy, it's very hard to resist the urge to scratch.

Scratching can damage your skin, causing more inflammatory substances to be produced that, in turn, cause more white blood cells to respond to this reaction. This increases the redness and itching, which makes it harder to resist scratching.

This process is known as the itch-scratch-rash cycle and it can become so severe that it causes sleeplessness, irritability, stress, thickening skin, and intense pain. Scratching can tear or scrape the skin, causing it to bleed and ooze, allowing bacteria to enter which can cause secondary infections to develop.

Generally, treatments like topical steroids and antihistamines work to relieve the symptoms of eczema once they have already appeared. Since the approval of treatments called Topical Calcineurin Inhibitors in Canada some dermatologists consider these agents to be a worthy addition to the treatment arsenal. Topical Calcineurin Inhibitors (TCIs) appear to prevent the release of the inflammatory substances that cause the red, itchy skin associated with eczema. This treatment works to calm and control the skin's reaction. In 2010 Health Canada approved one of the available TCIs for maintenance therapy. Talk with your doctor; he or she has the most up to date information about eczema treatments.

What is an eczema 'flare up'?

By nature, eczema symptoms can come and go. At times, symptoms can be more severe, or the rash and itching can completely disappear for long periods at a time. However, when symptoms suddenly reappear or become worse, it is called a 'flare up'. A number of different factors appear to trigger 'flare ups' of eczema.

'Flare ups' can happen when your skin comes in contact with irritants like soap, detergents, abrasive clothing (e.g. wool and synthetic fibres), perfume, carpet fibres, or dust. Overheating, excessive sweating, or low humidity can also trigger a 'flare up'.

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