Eczema is an umbrella term used to describe a series of skin conditions that share common characteristics, such as dry, itchy or irritated patches of skin with a rash-like appearance. Sometimes people can have more than one type of eczema at the same time.
Each form of eczema has its own set of triggers and treatment requirements. That’s why it’s so important to consult with health care providers who specialize in treating eczema. Dermatologists in particular can help identify which type or types of eczema you may have and how to treat and prevent flare-ups.
The scattered circular patches of nummular eczema, which takes its name from the Latin word for coin, are often misdiagnosed, leading to treatment with medications that don’t work and patients who struggle to clear their skin.
Nummular eczema can look like psoriasis, ringworm, fungal infection and other types of eczema, including atopic dermatitis, stasis dermatitis and contact dermatitis. It can also occur along with those types of eczema, though it often appears as an isolated condition.
All of this means diagnosis can be challenging for physicians who aren’t skin specialists, particularly when the condition first develops, according to Peter Lio, MD, clinical assistant professor of dermatology and pediatrics at Northwestern University’s Feinberg School of Medicine in Chicago.
“Dermatologists usually have the advantage of seeing things later in the game, when symptoms are more fully manifested. It can be much trickier to diagnose and treat when it is just starting,” says Lio, who is the founding director of the Chicago Integrative Eczema Center.
The good news is that the right medications and good self-care can often improve symptoms quickly.
Symptoms of nummular eczema
Nummular eczema commonly affects the legs and is also seen on the torso, hands and in areas where eczema doesn’t usually develop, such as the pit of the elbow.
Itching is a major symptom and a quality-of-life issue for patients, who may also be embarrassed by the rash’s appearance.
“Patches of nummular eczema frequently have oozing and crusting that’s more pronounced than with typical eczema,” says Lio, who notes that severe cases can be painful.
Who gets nummular eczema and why
Nummular eczema can occur at any age, and boys and men tend to develop it more often than girls and women. Dermatologists can usually spot the condition but may take a skin scraping to confirm a diagnosis.
Its causes aren’t clear, but triggers can include very dry or sensitive skin and trauma to the skin from insect bites, scrapes or chemical burns.
Nummular eczema may also develop as a reaction to some other types of eczema and their triggers, such as contact dermatitis and nickel. When it appears on the legs, it can be linked to poor blood flow in the lower body and the stasis dermatitis those circulation problems can cause.
Like atopic dermatitis, patches of nummular eczema are often infected with staphylococcus (staph), which needs to be treated along with the skin inflammation to clear the condition, says Lio.
Treating nummular eczema
Unlike some other forms of eczema, the nummular type seldom improves without relatively aggressive treatment, says Lio. He often sees patients with nummular eczema who have been treated with antifungal or antibacterial creams or with low-potency topical corticosteroids. These medications rarely improve symptoms.
“Unlike atopic dermatitis, which usually will eventually cool down even with minimal treatment, nummular eczema tends to laugh in the face of mild treatments, and an appropriately strong steroid is needed,” he says.
He typically prescribes a mid- or high-potency topical corticosteroid, along with a topical antibiotic. If eczema patches are substantially weepy and oozy, Lio usually has patients apply an astringent compress for a few days to help dry the area and drive out any staph infection.
The prognosis for most patients is excellent, Lio says.
“Once we identify nummular eczema and treat it appropriately, most people are significantly better within seven to ten days, and, for patients who don’t have another type of eczema, it often never comes back,” he says. “Even in those for whom this is a manifestation of their underlying atopic dermatitis, the nummular aspect seems to disappear quickly and then we can go back to overall management.”
Keeping the skin hydrated with good moisturization practices can help prevent flares of nummular eczema. When the condition is active, Lio advises covering affected skin and washing hands frequently to prevent the spread of staph infection.