What are the aims of this leaflet?
This leaflet has been written to help you understand more about discoid eczema. It tells you what it is, what can be done about it, and where you can find out more about it.
What is discoid eczema?
Eczema (also called dermatitis) is a term used to describe conditions where there is inflammation affecting mainly the outer layer of the skin (the epidermis). There are several different types of eczema, and in some cases the cause is known whilst in others it is not. Discoid eczema is one type of eczema with characteristic round or oval red patches of inflamed skin. Discoid eczema is sometimes also called “nummular” eczema - nummular meaning coin-shaped and discoid meaning disc-shaped.
Discoid eczema can occur at any age but is seen more frequently in adults. It is slightly more common in adult men than women.
What causes discoid eczema?
Often the cause of discoid eczema is unknown and is considered a distinctive type of eczema. However, similar appearances of round or oval red patches of skin can occur in other types of eczema, particularly atopic eczema. It can also occasionally be triggered by skin contact with irritants or allergens (contact dermatitis). In some people discoid eczema can be made worse by body washes, moisturisers or other materials coming to contact with the skin.
In some people discoid eczema may arise in old scars or areas where the skin has been damaged. Individuals with a type of eczema called irritant contact dermatitis of the hands may also develop discoid eczema elsewhere on the limbs or body.
Like other types of eczema, discoid eczema can be worsened by heat, sweating, scratching, local infection, and dryness of the skin.
Is discoid eczema hereditary?
No, it cannot be inherited.
What are the features of discoid eczema?
The typical lesions of discoid eczema are coin-shaped red patches of skin which are extremely itchy.
Each patch begins as a small group of red spots and tiny bumps or blisters, which cluster together and grow rapidly into a red, swollen, round patch which often weeps or develops a crusted surface. Lesions may become infected at a later stage. After a while the patches become dry and scaly.
There may be several patches on each limb and on the body, often in a symmetrical distribution, which develop over weeks to months. Most patches are between 1-3 cm in diameter, although they can be larger. As they progress some patches may become circular in shape with clear (normal) skin in the middle.
If untreated, discoid eczema may persist for months or years, often worsening and improving. It may come back at the same sites each time. This can also be seen if treatments are stopped too soon.
Patches may disappear without a trace, though in people with darker skin, light or dark marks may persist for months after the condition has cleared.
How will it be diagnosed?
Discoid eczema is usually diagnosed by its typical round or oval appearance. Sometimes it is misdiagnosed for a fungal infection. Tests may sometimes be needed to rule out other conditions; these may include:
- A skin biopsy - this is when a small sample of skin is cut out to look at under the microscope.
- Patch tests which identify whether a substance that comes in contact with the skin is causing inflammation of the skin, a condition called allergic contact dermatitis.
- Skin scrapings - skin scales are examined for signs of a fungal infection.
- Swabs may be taken to check for a bacterial infection.
Can discoid eczema be cured?
No, treatments help to control the condition, but do not cure it. The treatments may put the condition into remission, which means that there may be no signs of it for a period of time, but it can then come back. Whilst discoid eczema has been known to disappear for no apparent reason, there is no guarantee that it will not reoccur.
How can it be treated?
- Mild topical steroids are not usually strong enough to treat inflamed active discoid eczema. The mainstay of treatment is a potent or super potent steroid cream or ointment. This should be applied as prescribed to all affected areas, avoiding the surrounding normal skin, until the redness and swelling subsides. Treatment should be restarted at the first sign of recurrence.
- Combination creams or ointments with steroid and antibiotics or antiseptics may be useful.
- Other prescribed non-steroid creams such as tacrolimus ointment or pimecrolimus cream may also be helpful to reduce inflammation.
- If infection occurs an antibiotic may be necessary, either as a combined preparation with the topical steroid or in tablet form.
- An emollient (moisturising) cream or ointment is usually helpful. It is essential if the surface of areas affected by discoid eczema are dry and scaly. This should also be applied to unaffected skin, especially if it is dry. The emollient should be continued long-term, even after the patches have cleared and the steroid preparation has been discontinued. Avoidance of things which can irritate the skin such as detergents and use of an emollient instead of soap is also recommended.
- Occasionally, ultraviolet light treatment may be recommended by your dermatologist. Courses of steroid tablets may be required for very severe discoid eczema, but this treatment is rarely needed. Persistent and troublesome discoid eczema is occasionally treated with immunosuppressant medications such as methotrexate, azathioprine, ciclosporin or dupilumab.
CAUTION: This leaflet mentions ‘emollients’ (moisturisers). Emollients, creams, lotions and ointments contain oils which can catch fire. When emollient products get 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 very careful near naked flames to reduce the risk of clothing, hair or bedding catching fire. In particular smoking cigarettes should be avoided and being near people who are smoking or using naked flames, especially in bed. Candles may also risk fire. It is advisable to wash clothing daily which is in contact with emollients and bed linen regularly.
Where can I get more information about discoid eczema?
Web links to detailed leaflets:
Links to patient support groups:
National Eczema Society
11 Murray Street
Tel: 0800 089 1122
For details of source materials used please contact the Clinical Standards Unit (firstname.lastname@example.org).
This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.
This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel
BRITISH ASSOCIATION OF DERMATOLOGISTS
PATIENT INFORMATION LEAFLET
PRODUCED DECEMBER 2006
UPDATED DECEMBER 2009, APRIL 2013, JUNE 2016, AUGUST 2019
REVIEW DATE AUGUST 2022