The term “psoriasis nummular” is actually a bit confusing as the skin condition that produces weepy, oozy coin-shaped plaques is more often associated with eczema or dermatitis, and not necessarily psoriasis.
“Nummular” is a word derived from the Latin word for “coin” and is descriptive of the coin-shaped, itchy or non-itchy spots that can appear on the skin. Often these spots can be scaly and dry, but they can also become oozy and open.
Nummular eczema is often confused with nummular psoriasis, but it is important to realize that it is a type of eczema and NOT psoriasis.
While nummular eczema does not seem to be genetic, the actual cause is unknown, whether from an insect bite, winter dry skin, or an inflammatory reaction. However, nummular eczema can be confused with ringworm, so it is very important that you see a doctor and get a fungal culture done to make sure it is NOT ringworm.
Another reason to see your doctor for any type of nummular dermatitis is that it can get infected, usually due to scratching. The most common bacterial infection associated with nummular eczema is staphylococcus, which can become a serious systemic infection if left untreated.
Like many forms of psoriasis, nummular eczema can benefit from moisturizers, which protect the damaged skin and calm the irritation. Your physician may also prescribe a steroid cream to calm the inflammation. While the milder steroid creams don’t appear to be very effective the more powerful steroid creams have proven to be very beneficial in clearing up this type of skin condition.
When steroid creams may not be the right treatment, non-corticosteroid topical medications such as pimecrolimum (Elidel) or tacrolimus (Protopic) may be prescribed. Known as “topical calcineurin inhibitors”, these medications can be used by both adults and children older than two years.
When an infection does develop, topical or even oral antibiotics may be prescribed. For the annoying night-time itchiness, oral antihistamines have proven effective.
Psoriasis nummular may also be a term used, incorrectly, to describe nummular dermatitis. However, nummular dermatitis is actually the same thing as nummular eczema, otherwise known as “discoid eczema”.
Again, this type of dermatitis appears as distinct, round or oval-shaped sores on the skin, often appearing after an injury to that particular area. The skin injury may have been caused by a friction burn, insect bite, or other type of skin burn.
The patches may be singular or may show up as numerous spots, and can last for weeks or months.
One interesting thing about nummular eczema or dermatitis (psoriasis nummular) is that men tend to get it more often than women. Usually the first outbreak for men will occur after the age of 55, whereas women who get it are usually teenagers or young adults.
The good news is that with the right treatment, nummular eczema or nummular dermatitis usually disappears completely, unlike psoriasis. Some sores, especially those on the legs, thighs, and feet can take longer to clear up, and have a tendency to permanently mar the skin with lighter or darker spots.
Sometimes it can take up to a year for the condition to clear, while other people can have the condition for years before it finally clears. Then sometimes, just when you think it’s gone for good, it returns. Those patches that do return usually appear in the same location as the original outbreak.
So while eczema nummular or nummular dermatitis may be mistaken as psoriasis, and even wrongly identified as “nummular psoriasis”, this type of skin condition is not actually related to psoriasis.