HealthCentral recently highlighted new research out of Harvard Medical School on the role of Staphylococcus aureus (S. aureus) in itch. Researchers found S. aureus can trigger itch in mice and human cells through communication with sensory neurons.
For an expert’s take, I reached out to Gil Yosipovitch, MD, professor, Stiefel Chair of Medical Dermatology and director of the Miami Itch Center at the University of Miami Miller School of Medicine’s Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery.
What are your thoughts on the research published in Cell that Staphylococcus aureus interacts directly with nerve cells and can cause itch?
This is groundbreaking research that demonstrates that S. aureus in AD is secreting a specific protease that activates a receptor — PAR1 in nerves — to induce itch.
How does this research fit with the other emerging insights into the mechanism of itch in eczema?
We now better understand skin microbiome cross talk with nerves to induce itch. This now explains why when we would give oral antibiotics or use hypochloric acid wash that killed staph, patients stated it improved their itch.
What do we know now about the prevalence of S. aureus in eczema patients? What’s still unknown?
The prevalence of S. aureus colonization is 55-100% of AD patients compared to 10-30% of patients with healthy skin. We still need to know better techniques to reduce S. aureus without damaging other good bacteria that reside in the skin.
How can this new research as well as other data give insight into how to stop eczema itch?
There are many mechanisms that cause itch in AD and interventions beyond eliminating S. aureus, including drugs that block type 2 inflammation. It is also clear that drugs that target type 2 inflammation reduce S. aureus in the skin and improve the skin barrier to fight against these germs. Other advances, such as a better understanding of the mechanisms of stratum corneum pH (acidic pH kills the staph), are in development. In addition, prebiotics, probiotics and postbiotics have been developed, but the optimal time to start therapy and the optimal dosing and duration needed to see beneficial effects are not clear.
What else should every dermatology clinician know about eczema itch and how to treat it?
The research in eczema itch is advancing rapidly. There are many newly discovered pruritognes, cytokines and neuropeptides, such as OSM, IL31, OX-40, Periostin, MRGPRX2 and Brain Natriuretic Factor, to name a few. Drugs that are more potent than those currently available are in ongoing clinical trials from phase 1-3. We believe that in the next decade disease-modifying drugs will be available that may change the trajectory of the disease and itch, and patients may not require drugs for prolonged durations for the rest of their lives. We will have more understanding of biomarkers for itch and personalized medicine, however, there will be no one drug that fits for all as there is a diverse pathophysiology of itch in AD.
Did you enjoy this Patient Buzz expert commentary? You can find more here.
