Discoid or nummular dermatitis appears as round or oval coin-sized areas of itchy, inflamed, flaking or cracked skin. It will start as a small red spot and lesions can appear singly or in numbers anywhere on the body (being worse on the limbs), but it does not normally occur on the face or scalp.17

Small bumps or blisters may be present within the inflamed areas, and as it flares up, the skin can start oozing and crusting over. Itching can be particularly bad, and worsen at night, and scratching increases the risk of infection taking hold. Over time, the surface becomes scaly with the centre of the disc clearing but then left dry and flaky.17,18

Men are more prone to develop discoid eczema once they are in their 50s, whereas it is more likely to first appear in women in their late teens or twenties. It is uncommon in children but can appear at any age.19

Some people with discoid eczema also have a history of atopic dermatitis, but discoid eczema does not appear to run in families, unlike atopic eczema.17

It has been associated with certain medicines including interferon and ribavirin when used together to treat hepatitis C, tumour necrosis factor-alpha (TNF-alpha) blockers used in arthritis, and statins. It is also associated with excessive bathing or swimming.17,20