What is the neuroimmune link, and what does it mean for managing atopic dermatitis?
Our understanding of atopic dermatitis (AD), the most common form of eczema, has been evolving rapidly. Historically, AD has been understood to be an inflammatory skin condition, but until recently, little was known about exactly what causes AD. Over the past two decades, we have learned a lot about the skin barrier and how a “leaky” skin barrier allows irritants in and moisture out. In recent years, has gained a deeper understanding of the role of a dysregulated immune system. Now, we are learning more about the neuro-immune connection (also known as the communication between the nervous and immune systems) in AD.
ESC turned to Dr. Mark Kirchhof, an Ottawa-based dermatologist with a PhD in immunology, to learn more about this concept.
The Role of the Immune System
The immune system’s job is to protect the body from germs and allergens. In people with eczema, their immune system can overreact to these irritants, and this overreaction (or hyperactivity) causes the skin to react with AD flares, becoming red, inflamed, and very, very itchy.
The Role of the Nervous System
In AD, the immune system overreacts, triggering the feeling of itch in the skin, but the nervous system also plays a role. The nervous system sends signals to the brain to scratch the itch, resulting in the itch/scratch cycle in AD. Inflammation occurs, creating itch, and the impulse to scratch arises, leading to continued scratching that can worsen the flare cycle.
The research is also showing us that stress and anxiety can trigger an immune response, worsening AD. AD can also make the nervous system more sensitive and tell the brain to scratch, even if the itch is ‘minimal’. It is also known that in people with AD, the skin is incredibly sensitive, the itch response is heightened, and the impulse to scratch is helpful, as it is the body trying to rid itself of invaders.
What causes Atopic Dermatitis?
We now know that AD is caused by a combination of factors, including an impaired skin barrier, a hyperactive immune system, and hypersensitive nerves in the skin.
What does this mean for AD management?
Understanding the causes of AD can help us manage the condition and its flares. We work to strengthen the skin barrier with appropriate bathing and moisturizing. We can also manage flares when they occur with topical therapy. When AD is more severe or doesn’t get better, we can address the overactive immune system and nervous system with advanced medicines that a specialist, like a dermatologist, may recommend.
It’s also important for patients and caregivers to understand that this difference in skin sensations has practical impacts on life for people who live with AD. People with AD may be more sensitive to temperature fluctuations and to sensations on the skin, such as the rubbing of fabrics or touch. Even moisturizers or topical treatments may be uncomfortable.
What can we do?
The good news is that patients don’t need to suffer; a specialist, such as a dermatologist, can help.
Eczema Society of Canada thanks dermatologist Mark Kirchhof, MD, FRCPC, for his contribution to this educational content.
This content was created as part of the 2025 Life with Eczema educational program.
Disclaimer: Information provided in this resource does not constitute medical advice and is not intended to be used as a diagnostic tool. The information is up-to-date at time of publication. All medications, interventions, and treatment plans have risks and benefits, and it is important that individuals discuss their or their child’s specific healthcare needs with a qualified healthcare professional.
