What is Atopic Dermatitis?

When you think about atopic dermatitis, what probably comes to mind is the itchy, burning rash you can see. But there’s a bigger story going on beneath the skin.

Atopic dermatitis, a chronic form of eczema, is more than a skin condition. It’s a disease caused in part by an overreaction of your body’s natural defense system.

Understanding what happens on the inside may help you better manage the symptoms of atopic dermatitis. Watch the video to learn more.

While the redness and rash of atopic dermatitis are visible on your skin, the real story may be happening beneath the surface.

Atopic dermatitis is more than a skin condition. It's a disease caused by an overactive immune system that leads to inflammation in your body.

It is the internal inflammation that causes the symptoms you know.

Atopic dermatitis is called the “itch that rashes” for a reason.

While scratching may offer short-term relief, in the long run you're actually making your atopic dermatitis—and the itch—worse.

This is called the itch-scratch cycle.

Your skin has 3 layers.

In healthy skin, the tough outer layer called the epidermis keeps foreign substances such as bacteria, viruses and allergens from getting in.

When you have atopic dermatitis, the outer layer of skin is weaker and more susceptible to inflammation caused by immune cells in the body.

The damage done by scratching also contributes to the breakdown of skin cells, making it easier for foreign substances to get in.

Once these foreign substances have broken through the skin barrier, immune cells alert the body that it's under attack.

These immune cells travel to the lymph nodes, which are in the second layer of skin, called the dermis. Once in the lymph nodes, these immune cells activate your body’s defenders, called T helper cells.

The immune cells release substances that cause the familiar redness and rash on the skin's surface.

Although these substances normally go away after a short time, if you have atopic dermatitis, the cells don't switch off like they should. Instead, they continue the inflammatory process, so the skin continues to react, even when your skin looks clear.

Even when you have no visible rash, the underlying inflammation is still active beneath your skin.

The itching leads to scratching, which further weakens the skin cells in the epidermis, allowing more foreign substances to get in and increases your risk of infection. And the itch-scratch cycle continues.

Understanding the Causes

Eczema that occurs chronically may be more than just a skin condition. It could be a disease called atopic dermatitis.

The most common type of eczema is atopic dermatitis, a chronic disease. If you struggle with frequent flare-ups that just keep coming back, there may be a bigger story happening inside your body.

With atopic dermatitis, even when your skin looks clear, the inflammation may still be active under the surface and your next flare-up is just waiting to return. Some people always show signs of the disease.

The most obvious sign of atopic dermatitis is dry, itchy skin. Flare-ups are different for every person and can appear all over the body. Some other common external symptoms include:

  • Redness
  • Lesions that can ooze and crust
  • Swelling
  • Scaly areas
  • Thick skin

But the rashes on the surface are only part of the story. The impact can go deeper than the skin. In fact, the majority of people with moderate-to-severe atopic dermatitis report that itch can delay falling asleep and occasionally or frequently wakes them up at night. To really understand atopic dermatitis, you have to look at the deeper cause within your body.

Scratching the Surface

Atopic dermatitis is an immunological disease, which means it involves the immune system.

With atopic dermatitis, your immune system is highly sensitive and can react to even the smallest allergens or irritants. This reaction can cause excess inflammation underneath your skin, which may lead to your frequent flare-ups. So those rashes you see on the surface are just the visible signs of a deeper inflammatory disease.


In people with atopic dermatitis, internal and external stimuli irritate the skin, causing nerve endings and immune cells to overreact. The resulting inflammation and intense urge to scratch has given atopic dermatitis the name "the itch that rashes".


When you scratch, you can break down the outer layer of skin which allows bacteria, viruses and allergens to get in, leaving it prone to infection.


In response to these invaders, your immune system continues to send signals to the surface, causing even more redness and itching.


The more you scratch, the more your skin barrier breaks down and the itch-scratch cycle continues.