Introduction

Discoid eczema, also known as nummular or discoid dermatitis, is a long-term skin condition that causesskin to become itchy, reddened, swollen and cracked incircular or oval patches.

Without treatment, discoid eczema can last for weeks, months or even years. It may also keep recurring oftenin the same area that was affected previously.

This topic covers:

Symptoms

When to seek medical advice

Causes

Treatment

Other types of eczema

Symptoms of discoid eczema

Discoid eczema causes distinctive circular or oval patches of eczema. They can affect any part of the body, although they don't usually affect the face or scalp.

Thefirst sign of discoid eczema isusually a group of small red spots or bumps on the skin. These then quickly join up to form largerpink, red or brown patches that can range from a few millimetres to several centimetres in size.

Initially, these patches are often swollen, blistered (covered with small fluid-filled pockets) and ooze fluid. They also tend to be very itchy, particularly at night.

Over time, the patches may become dry, crusty, cracked and flaky.The centre of the patch also sometimes clears, leaving a ring ofdiscoloured skin that can be mistaken for ringworm .

You may just have one patch of discoid eczema, but most peopleget several patches. The skin between the patchesis often dry.

Patches of discoid eczema can sometimes become infected. Signs of an infection can include:

• the patches oozing a lot of fluid
• a yellow crust developing over the patches
• the skin around the patches becoming red, hot, swollen, and tender or painful
• feeling sick
• chills
• feeling unwell

When to seek medical advice

See your pharmacist or GP if you think you may have discoid eczema so they can recommend a suitable treatment.

You should also seek medical advice if you think your skin may be infected. You may need to use antibiotic cream or, in severe cases, take antibiotics.

Your GP should be able to make a diagnosis just by examining the affected areas of skin. In some cases they may also ask questions or arrange some tests to rule out other conditions.

Your GP may refer you to a dermatologist (a doctor who specialises in managing skin conditions) if they're unsure of the diagnosis or if you need patch testing.

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 can't provide an effective barrier against substances that come into contact with it. This could allowa 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 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 doesn't 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're used together to treat hepatitis C
• tumour necrosis factor-alpha (TNF-alpha) blockers 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.

Treating discoid eczema

Discoid eczema is usually a long-term problem, but medications are available to help relieve the symptoms and keep the condition under control.

Treatments used include:

• emollients moisturisers applied to the skin to stop it becoming dry
• topical corticosteroids ointments and creams applied to the skin that can help relieve severe symptoms
• antihistamines medications that can reduce itching and help you sleep better

There are also things you can do yourself to help, such as avoiding all the irritating chemicals in soaps, detergents, bubble baths and shower gels.

Additional medication can be prescribed if your eczema is infected or particularly severe.

Occasionally, areas of skin affected by discoid eczema can be left permanently discoloured after the condition has cleared up.

Read about treating discoid eczema .

Other types of eczema

Eczema is the name for a group of skin conditions that cause dry, irritated skin. Other types of eczema include:

• atopic eczema (also called atopic dermatitis) the most common type of eczema, it often runs in families and is linked to other conditions such as asthma and hay fever
• contact dermatitis a type of eczema that occurs when the body comes into contact with a particular substance
• varicose eczema a type of eczema that most often affects the lower legs and is caused by problems with the flow of blood through the leg veins