Discoid eczema

What is discoid eczema?

Discoid eczema, sometimes referred to as discoid and nummular dermatitis, is a skin condition that causes circular or oval patches of swollen, cracked skin. They usually start as smaller spots or bumps, and can appear almost anywhere on your body.

The patches can range in size, and can be anywhere from a few millimetres up to several centimetres. They can cause severe itchiness, typically in the evening, and over time the patches can change appearance. At first, the affected areas are red or pink (or dark brown on darker skin), but over time they can become swollen, and might form a blister that contains fluid.^[1]

Discoid eczema can sometimes get infected. You should keep an eye on any affected areas that feel hot, swollen, or develop a yellow crust.

Who gets discoid eczema?

Discoid eczema can occur at any age. It’s rare in children, and is instead more likely to affect adults. Those who get discoid eczema often have other types of eczema at the same time, like atopic eczema or contact dermatitis.

Men who are aged between 50-70 are more commonly affected, as are teenage women and women in their twenties.

How common is discoid eczema?

It’s tricky to say just exactly how common discoid eczema is. It’s seen mostly in middle-aged adults,^[2] although it’s not fully understood why.

The most commonly affected parts of the body are the lower extremities (from your hips to your toes), arms and hands but discoid eczema patches can form nearly anywhere on the body. They don’t usually appear on the face or the scalp, though.

Discoid eczema has been associated with alcoholism,^[3] so you might be prone to developing it if you drink more than the recommended amount of units per week. It can also be drug-induced, so it’s worth checking if any medications you use might be having an effect.

What causes discoid eczema?

It’s not known why people develop discoid eczema. It’s thought that it has to do with the skin being dry, which then causes it to become aggravated.^[1]

When skin becomes dry, it loses its natural protective barrier. Without this barrier, it becomes more prone to irritation from the chemicals found in everyday toiletries and cosmetic products.

Often, people who have discoid eczema have atopic eczema, so it’s worth checking if any undiagnosed allergies are behind your symptoms. Unlike atopic eczema, discoid dermatitis doesn’t run in families.

What are the symptoms of discoid eczema?

Discoid eczema usually begins as small bumps or spots that show up on your skin, which then become larger, red-or-pink patches. Typically, several patches will start to appear, and they can range in size from a few millimetres to around two or three centimetres. They are often circular, or oval ‘discoid’ shapes, and can be asymmetrical (uneven).

The affected patches are usually swollen, and covered in tiny fluid-filled blisters. They often cause itching which is worse in the evening. The longer you have discoid eczema, the more the patches can develop and become dry and flakey. And if the blisters break, the patches can become infected.

Can discoid eczema lead to other problems?

Discoid eczema won’t develop into a more serious condition, but symptoms might bother you long-term if you don’t get them under control.

The patches of swollen and cracked skin on your body are also at risk of becoming infected the longer you leave them. Infection can also occur as the result of constant scratching, so getting the right help as soon as your symptoms develop will save you a lot of discomfort in the long run.