Eczema - discoid eczema

What is discoid eczema?

Discoid eczema (nummular eczema) is a type of eczema with characteristic round-oval patches of itchy inflamed skin. Discoid eczema can occur at any age but is seen more frequently in adults.

What does discoid look and feel like?

Discoid eczema can affect any part of the body, although it does not usually affect the face or scalp. It is often very itchy.

The first sign of discoid eczema is usually a group of small spots or bumps on the skin. These quickly join up to form discrete round-oval patches (sometimes referred to as coin-shaped) 1-3 cm in diameter. There may be several patches on each limb and on the body, which develop over weeks to months.

On lighter skin these patches will be pink-red. In skin of colour the patches can be a deep brown or occasionally paler than the skin around them.

Initially, these patches are often swollen, blistered (covered with small fluid-filled pockets) and ooze fluid. Over time, the patches may become dry and crusty.

What causes discoid eczema?

While the cause is largely unknown, eczema occurs as a result of the skin barrier becoming less effective, something that is more likely as we get older. Discoid eczema is not genetic and so does not run in families. It is considered a distinctive type of eczema, however, similar appearances of round or oval red patches of skin can occur in atopic eczema.

The skin barrier – bricks and mortar

The barrier function refers to the outer skin layer (the Stratum Corneum), which is analogous to a brick wall. In the skin the bricks are dried out, non-living cells called corneocytes. The bricks are held together by mortar/cement, referred to as the intercellular matrix; composed of lipids.

In healthy skin this brick wall is highly impermeable, keeping water loss to a minimum and preventing small particles such as irritants, allergens, and infection from getting into the skin.

In eczema (discoid, atopic, and other types) the skin barrier becomes less effective - this happens naturally as we get older (whereas in patients with a different type of eczema, atopic eczema, it arises as a result of a faulty gene). Essentially, the bricks are crumblier and the mortar/cement is less effective at holding everything together, resulting in too much water escaping from the skin (the skin dries out), and allowing more irritants and allergens to penetrate the skin, causing itching and inflammation. Accordingly, managing the skin barrier effectively is one of the most important aspect of treating any type of eczema.

Things you can do to help yourself

• Protect your skin by avoiding irritants such as soaps, bubble baths, detergents, and contact with other chemicals. Certain materials worn next to the skin such as wool and synthetic fabrics can also aggravate eczema; stick to soft, fine-weave clothing or natural materials such as cotton

• Help repair the skin barrier with emollient moisturisers - these come in the form of creams, gels, and ointments. Creams and gels are better tolerated, ointments are more effective if the skin is very dry. The most important aspects of treatment are - use the one that suits you most, use large amounts (500-2000 grams per month), apply to the whole skin, aim to use twice a day as a minimum, and know how to apply. This link shows how to apply moisturisers (emollients)

• Do not wash (bath or shower) more than once a day, and for no more than 10-15 minutes - our skin does not like water. Avoid soaps and anything that makes a lather as this may damage the skin, instead apply an emollient cream (moisturising cream) onto your skin before you get into the bath/shower, and then wash off in the water. Take care not to slip - using an emollient in this way is best avoided in people with poor balance and/or those who are more at risk of breaking a bone

• Heat and sunlight - if heat aggravates the skin, keep the rooms in your house cool, especially the bedroom. Most people’s eczema improves with careful sunlight exposure (always in moderation), although a few people find that sunlight makes their eczema worse

• Keep nails short and clean to minimise damage to the skin from unintentional scratching 

• See your pharmacist for advice on the use of emollients, and ask about a pre-payment certificate if you pay for prescriptions. Your pharmacist can also recommend mild steroid creams to use if the skin is inflamed that can be purchased without a prescription.

Make an appointment at your GP surgery

If your eczema is not responding to the measures described above, then make an appointment to see a health professional.

This link provides details on specific treatments.

General notes on treatment:

• Emollients - as discussed above. You must continue using these even if the eczema is settled, otherwise your eczema is likely to flare-up more often

• Steroid creams (or ointments, gels, lotions) - should be applied thinly and only to the affected patches of skin during flare-ups (when the skin becomes red and itchy). They must NOT be applied at the same time as a moisturiser, leaving a minimum of 20 minutes between the two applications (a good routine is important. Some people apply moisturisers in a morning and then after washing in an evening, followed by the steroid cream at bedtime). Discoid eczema may require treatment with one of the stronger (potent) steroid creams. This link explains how to apply steroids onto the skin

• Antihistamines - in most people, non-sedating antihistamines (which do not make you feel tired) do NOT help eczema. Sedating antihistamines (which make you feel tired) may help at night if the eczema is flaring and affecting your sleep. You need to be mindful that sedating antihistamines may affect your driving / ability to work the next morning. Sedating antihistamines must not be used regularly in the long-term as there is some evidence linking them to an increased risk of dementia (memory loss)

Your mental health

Eczema can have a significant psychological impact and may affect many areas of daily life including work and personal relationships. If the eczema is affecting your mental health the National Eczema Society offers helpful advice. If your mental health continues to be affected, then you should discuss this with a heath professional.

Referral to a specialist

The following groups of people may need to be referred to a specialist, who may be a dermatologist or a GPwER/GPwSI in Dermatology (a GP who has been trained in relevant areas of Dermatology):

• If the diagnosis is unclear
• Moderate-severe eczema not responding to treatments provided by a health professional

What will happen when you are referred?

Treatment options can include alternative topical treatments (creams, ointments, gels), a course of light treatment (phototherapy), oral medications (tablets) to lessen the immune reaction in your skin (immunosuppressive drugs), or injections.

Please take to your appointment a list of the treatments that you are currently using (and have used) for your eczema, as the specialist may not otherwise know.

Can discoid eczema be cured?

Unfortunately not, and if left untreated, discoid eczema may persist for months or years. Whilst discoid eczema has been known to disappear for no apparent reason, there is no guarantee that it will not reoccur.

Other helpful resources for eczema

• The National Eczema Society

CAUTION

This leaflet mentions ‘emollients’ (moisturisers). When emollient products come in contact with dressings, clothing, bed linen or hair, there is a danger that a naked flame or cigarette smoking could cause these to catch fire. To reduce the fire risk, patients using skincare or haircare products are advised to be incredibly careful near naked flames to reduce the risk of clothing, hair or bedding catching fire. Cigarette smoking (and being close to people who are smoking) should be avoided.

Helping with other skin conditions

If you, a family member, or friend have an undiagnosed skin condition; or you want to learn more about how to treat skin conditions, please view our short video on how to get the best from this website.