Nummular Eczema

What is nummular eczema?

Nummular eczema, also known as discoid eczema and nummular dermatitis, features scattered circular, itchy and sometimes oozing patches on the skin.¹ The word “nummular” comes from the Latin word for “coin,” as the spots can look coin-shaped on the skin.²

It usually develops on the legs, forearms or back of the hands.¹ If nummular eczema is caught early and treated properly, it can heal within 3 to 4 weeks.¹ Nummular eczema can return. If you had it once, it tends to come back and appear in the same place on the body.¹

Nummular eczema is one of the seven types of eczema. Nummular eczema is sometimes mistaken for ringworm or psoriasis.¹

What does nummular eczema look like?

The hallmark appearance of nummular eczema are the coin-shaped lesions from which it gets its name.² The round spots are slightly raised and can appear red or brown depending on skin tone. The oval spots are usually the first symptom of nummular eczema, and they can range in size from 1-10 cm.² As a flare develops, the spots become bumpy instead of flat.

Over time, the bumps can change between red, pinkish or brown in color. They often become scaly and inflamed as well.² As the flare persists, the skin around it can become dry and this dry skin may crack.² Oozing liquid can come out of lesions or lesions can crust over.

Who gets nummular eczema?

Nummular eczema can occur at any age. Males tend to develop nummular eczema more often than females. Interestingly, men and women get their first episodes of nummular eczema at different times. Women usually develop nummular eczema before the age of 30 and men after the age of 50.² It predominantly affects women 15 to 25 years old and men 50 to 65 years old.¹ It’s also possible for young children with atopic dermatitis to develop nummular eczema, though this isn’t as common.¹

You’re also more likely to develop nummular eczema if you have a family history of atopic dermatitis, hay fever or asthma.²

If you have atopic dermatitis, contact dermatitis, stasis dermatitis or blood circulation problems, you have a higher risk for nummular eczema.^{1, 3}

Is nummular eczema contagious?

No, nummular eczema is not contagious.¹ You cannot catch it or spread it to others.

Is nummular eczema life-threatening?

When managed, nummular eczema is not a serious condition. Flares can be uncomfortable and disrupt daily life, but managed nummular eczema is not life-threatening. However, the condition can become more serious when left unchecked. That’s because skin infections (such as staph bacteria) can form in nummular eczema patches.⁴

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What causes nummular eczema?

The exact cause of nummular eczema is not known.³ This skin condition typically appears during the winter when the air is dry and heat is on leading to skin dryness. Other causes have been speculated to include trauma to the skin, like an insect bite, scrape or chemical burn.³ Nummular eczema often appears on the legs because it is the dryest part of our body partly caused by poorer blood flow, especially as we age.^2,3

Your chances of getting it may also increase if you have certain risk factors, such as having another form of eczema or poor blood circulation.³

Current research has linked the development of nummular eczema to several factors. If you have dry skin or decreased skin oil production, you are more likely to develop nummular eczema.^1,2 Certain allergic reactions can trigger nummular eczema, such as a contact allergy to metals or environmental airborne allergens.^2,3 People living in environments with low humidity are also at higher risk.^2,3

Some behaviors, products and medicines can also trigger nummular eczema, such as the use of drying soaps, frequent bathing with hot water, exposure to rough fabrics such as wool, breast implantations and certain medications (antivirals, interferon or retinoids).^1,2,3

What triggers nummular eczema and causes a flare?

Some common triggers of nummular eczema include:

• Very dry or sensitive skin¹
• Trauma to the skin such as scrapes or chemical burns¹
• Bug bites¹
• Drinking alcohol³
• Starting medications that can dry skin³
• Intense stress³
• Dry air³
• Skin infections such as staph (staphylococcal colonization)²

Things that decrease the skin’s moisture barrier, such as harsh soaps and long, hot, frequent showering can increase symptom severity or lengthen the amount of time you have symptoms.^1,2

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What are the symptoms of nummular eczema?

Common symptoms of nummular eczema include:

• Round-shaped spots that are raised on arms, legs, torso and/or hands⁴
• Tiny bumps and blister-like sores after an injury like a scrape⁴
• Scaly spots that crust over and join together
• Itching and burning in affected areas
• Lesions that ooze liquid⁴
• Red, pinkish or brown spots, depending on skin tone⁴
• Skin between the spots is extremely dry⁴

Where on the body does nummular eczema occur?

It can occur on any part of the body, however nummular eczema usually pops up on the forearms, hands or legs.¹

It is possible to have just one patch of nummular eczema. However, it is more common to have multiple patches on your body. Typically, these patches are concentrated in one area of the body, such as the hands or legs, though this isn’t always the case.¹

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How is nummular eczema diagnosed?

Nummular eczema can look like psoriasis, ringworm, a fungal infection, and even other types of eczema, including atopic dermatitis, stasis dermatitis and allergic contact dermatitis.¹ That’s why it’s important to get an accurate diagnosis from a healthcare provider.

To determine if your symptoms are from nummular eczema or something else, a dermatologist will examine affected areas of the skin. Your dermatologist may take a skin scraping to confirm a diagnosis.^2,5 The provider will also ask about your medical history, including if you have experienced other forms of eczema. It’s important for a dermatologist to know your overall history with eczema before developing a treatment plan.

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How is nummular eczema treated?

Nummular eczema can be treated with a mid- or high-potency topical corticosteroid. Your doctor might also prescribe tacrolimus ointment, pimecrolimus cream, ruxolitinib cream, tapinarof cream, or roflumilast cream for treatment.⁵

If nummular eczema is also infected with Staphylococcus aureus (staph), it needs to be treated with a topical or oral antibiotic.⁵

If the nummular eczema patches are substantially oozing fluid or pus, application of an astringent compress can help dry the area.

Widespread nummular eczema and severe cases may need more than one treatment option. Your dermatologist should give you clear instructions for how to care for the lesions, along with the necessary medications. A dermatologist may also prescribe phototherapy, a form of light therapy which uses ultraviolet lights.⁵ This is especially the case if there are blisters or an eczematous rash.

Learn more about available treatments for eczema

How do you manage nummular eczema symptoms?

Other treatments to manage symptoms include:

• Wet wraps
• Antihistamines
• A humidifier
• Topical steroids and non-steroidal medications
• Eczema-friendly cleansers and moisturizers designed for sensitive skin

How long does nummular eczema last?

Nummular eczema symptoms often clear after treatment, usually within three to four weeks.¹ There are some signs that your eczema flare is responding well to treatment. The most obvious sign is that the nummular eczema lesions begin to flatten.⁴ The center of the red spot often clears first, creating a ring instead of a fully formed circle.⁴ Eventually, the entire red spot will disappear. Sometimes it’s replaced by a flat dark spot.⁴ This discoloration is more likely in darker skin tones and is not a sign of an active nummular eczema flare.⁴

How can I tell if my nummular eczema is infected?

If you scratch the affected areas too much, it can weaken the skin barrier. A weak skin barrier is more susceptible to skin infections and an overall weaker immune system. Infected patches of nummular eczema often develop golden or yellowish crusting.⁴

If you believe your nummular eczema is infected, consult with your dermatologist or primary care provider as soon as possible. They will likely have to prescribe medication to help your body overcome the infection.⁵