What is nummular eczema (nummular dermatitis or discoid eczema)?
Nummular eczema (also known as discoid eczema and nummular dermatitis) is a form of eczema that can occur at any age. It looks different than other types of eczema and can be difficult to treat because it seems to affect people differently.
The word “nummular” comes from the Latin word for “coin,” as the spots can look coin-shaped on the skin. The spots may be very itchy or not itchy at all. They can be very dry and scaly or can become wet and open.
The cause of nummular eczema (nummular dermatitis) is unknown, but it does not seem to run in families.
Known triggers for nummular eczema include:
- Damage to the skin such as through an insect bite, scrapes and scratches, chemical “burns”
- A reaction to inflammation (as with atopic dermatitis and/or statis dermatitis) elsewhere on the body
- Dry skin especially in the winter
- Metals like nickel
- Poor blood flow or swelling in the lower legs
- Medications like topical antibiotic creams, isotretinoin and interferon
Because nummular eczema (nummular dermatitis) can look like ringworm, it is important to make sure that it is not a fungal infection, especially if it is not responding to treatment. This can usually be done by your health care provider with a skin scraping or a fungal culture.
Like atopic dermatitis, nummular eczema (nummular dermatitis) can get infected by bacteria — usually staph. Make an appointment with your doctor if you think you have an infection on your skin where the nummular eczema appears.
Nummular eczema appears more frequently in men, usually between the ages of 55-65. Women usually get their first flare of nummular eczema between the ages of 13-25. It can also affect children.What does nummular eczema – nummular dermatitis look like?
Symptoms of nummular eczema (nummular dermatitis) include:
- Coin-shaped lesions on arms, legs, torso and/or hands
- Itching and burning
- Lesions that are oozing liquid or have crusted over
- Red, pinkish or brown, scaly and inflamed skin around the lesions
Nummular dermatitis treatment
Like atopic dermatitis, nummular eczema (nummular dermatitis) benefits from moisturizers to calm and protect the damaged skin barrier.
In many cases, you may receive a prescription for a steroid medication to calm the inflammation as well. For some reason, the milder and moderate-potency steroid creams may not be of much help with nummular eczema (nummular dermatitis). More powerful steroid creams are frequently required. Fortunately, nummular eczema (nummular dermatitis) tends to disappear completely after the right treatment.
In cases where steroids are not appropriate, or when you have used them for a long time, your doctor may prescribe phototherapy, coal-tar creams, or a non-corticosteroid topical medication such as tacrolimus (Protopic) or pimecrolimus (Elidel). These medications are called topical calcineurin inhibitors (TCIs) are approved for use by adults and children two years of age or older.
Topical or oral antibiotics may be used when there is a bacterial infection on the skin. In very severe cases, systemic steroids (taken by mouth or given by injection) may be used for a short time to calm symptoms, though they are not recommended.
Atopic dermatitis may look like nummular eczema, especially on people of African-American or Asian descent.
Will nummular eczema ever go away?
Many people, even those who have a severe nummular eczema, seem to clear up completely and do not appear to have the long-term issues like other forms of eczema.