Discoid eczema - Causes of discoid eczema

The cause of discoid eczema is unknown, although it may occur as a result of having particularly dry skin.

Dry skin means your skin cannot provide an effective barrier against substances that come into contact with it, which could allow a previously harmless substance, such as soap, to irritate (damage) your skin.

It's important to look carefully at all the chemicals in cosmetics and toiletries that may have come into contact with your skin.

Contact dermatitis, a type of eczema caused by coming into contact with a particular irritant, may therefore have a role in discoid eczema.

Some people with discoid eczema also have a history of atopic eczema, which often occurs in people who are prone to asthma and hay fever. However, unlike atopic eczema, discoid eczema does not seem to run in families.

Other possible triggers 

An outbreak of discoid eczema may sometimes be triggered by a minor skin injury, such as an insect bite or a burn.

Some medicines may also be associated with discoid eczema, as patches of eczema can appear in people taking:

• interferon and ribavirin – when they are used together to treat hepatitis C 
• tumour necrosis factor-alpha (TNF-alpha) blockers – which are used to treat some types of arthritis
• statins (cholesterol-lowering medication), which can cause dry skin and rashes

Dry environments and cold climates can make discoid eczema worse and sunny or humid (damp) environments may make your symptoms better.