Immune Pathways Driving Chronic Spontaneous Urticaria, With Harrison Nguyen, MD, MBA, MPH

Harrison Nguyen, MD, MPA, MPH, gave an interview with HCPLive during the Society of Dermatology Physician Associates (SDPA) 2025 Fall Conference in San Antonio regarding his conference talk on chronic spontaneous urticaria (CSU).1

Nguyen serves as a clinical assistant professor of dermatology at Baylor College of Medicine. His session, titled ‘The Itch Within: Immune Pathways Driving Chronic Spontaneous Urticaria,’ featured a discussion of the evolving understanding of the immunologic mechanisms in CSU, including the roles of mast cell disregulation, autoimmunity, and type 2b inflammation.

“CSU can be a tremendously impactful condition, with wheels lasting 6 weeks or longer,” Nguyen said. “What we know is more heterogeneous than I think we had originally anticipated. And this is why some patients don't respond to high-dose antihistamines, why they don't respond to treatment with omalizumab. What we did was we took a dive into the mast cell.”

Nguyen highlighted emerging basic science discoveries and their relationship with practical clinical insights in the CSU space. He was asked how such immune pathways inform diagnostic approaches and decision-making related to therapeutics.

“What we did was we took a dive into the mast cell,” Nguyen said. “I compared the mast cell to Dwight Schrute from The Office. For The Office fans out there, it's Dwight Schrute who is wreaking havoc on the body. So with Dwight Schrute and the mast cell, he can be activated by two different pathways, a type one and a type 2b. Type one is dependent on IgE, which leads to activation of the mast cell, and type 2b is more dependent on IgG. 50% of patients will have an overlap of the two.”

Nguyen touched on several key elements of the mast cell with this analogy, highlighting different pathways, such as the BTK pathway, leading to degranulation in the mast cell.

“But then we also looked at type 2 inflammation, which I compared to Michael Scott in The Office,” Nguyen explained. “He's the one who is creating the environment that leads to Dwight Schrute wreaking havoc. So if we can block type 2 inflammation, especially blockade of IL-4 and IL-13, it can improve patient symptoms with CSU.”

Nguyen sought to allow for a greater appreciation of the immunopathogenesis of CSU as well as its implications for current and future strategies for management of the disease.

For more information on CSU, view the full video posted above. To find out more from the conference, view our latest conference coverage.

The quotes used in this interview were edited for clarity.

Nguyen had no relevant financial disclosures of note

References

1. Nguyen H. The Itch Within: Immune Pathways Driving Chronic Spontaneous Urticaria. Presented at the Society of Dermatology Physician Associates (SDPA) Fall Conference, November 5-9, San Antonio, TX.