Eczema - discoid; Nummular dermatitis
Nummular eczema is a dermatitis (eczema) in which itchy, coin-shaped spots or patches appear on the skin. The word nummular is Latin for "resembling coins."
The cause of nummular eczema is unknown. But there usually is a personal or family history of:
Things that can make the condition worse include:
- Dry skin
- Environmental irritants
- Temperature changes
Symptoms may include any of the following:
- Coin-shaped areas of the skin (lesions) that are red, dry, itchy, and scaly, and appear on the arms and legs
- Lesions may spread to middle of body
- Lesions may ooze and become crusty
Exams and Tests
Your health care provider can usually diagnose this condition by looking at your skin and asking about your family's medical history.
A skin biopsy may be needed to rule out other similar conditions. Allergy testing may be done.
Eczema is often treated with medicines applied to the skin. These are called topical medicines, and may include:
- A mild cortisone (steroid) cream or ointment at first. You may need a stronger medicine if this does not work.
- Other ointments or creams that help quiet the immune response may be prescribed for anyone over 2 years old, often for use on the face or other sensitive areas.
- Creams or ointments that contain coal tar may be used for thickened areas.
You may also be asked to try the wet wrap treatment. This involves the following steps:
- Soak the skin in lukewarm water for about 10 minutes.
- Apply petroleum jelly (such as Vaseline) or corticosteroid ointment to the lesions.
- Wrapping the affected area with wet bandages to keep the skin moist. This also helps the medicine work. If larger areas of the body are affected, you can wear damp pajamas or a sauna suit.
- Follow your provider's instructions for how long to keep the area covered, and how many times a day to do the wet wrap treatment.
The following measures may help improve your symptoms or prevent them from returning if your skin has cleared:
- Use lukewarm water when bathing and showering. Hot water can dry and irritate the skin. Take shorter or fewer baths or showers.
- Don't use soap. It can dry the skin. Use a gentle, mild cleanser instead.
- Ask your provider about adding bath oil to bath water.
- After bathing or showering, pat the lesions dry and apply lotion before the skin is all dry.
- Wear loose clothing. Tight clothing can rub and irritate the skin. Avoid wearing rough fabrics, such as wool, next to the skin.
- Use a humidifier in your home to help moisten the air.
Nummular eczema is a long-term (chronic) condition. Medical treatment and avoiding irritants can help reduce symptoms.
When to Contact a Medical Professional
Contact your provider if you have symptoms of this condition.
Also contact your provider if:
- Symptoms continue despite treatment
- You have signs of infection (such as fever, redness, or pain)
There is no known way to prevent the disorder.
Habif TP. Eczema and hand dermatitis. In: Habif TP, ed. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 6th ed. Philadelphia, PA: Elsevier; 2016:chap 3.
James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM. Eczema, atopic dermatitis, and noninfectious immunodeficiency disorders. In: James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM, eds. Andrews' Diseases of the Skin. 13th ed. Philadelphia, PA: Elsevier; 2020:chap 5.