Distinct Clinical and Laboratory Profiles in Chronic Spontaneous Urticaria Requiring High-Intensity Treatment

Area of Science:

• Immunology
• Dermatology
• Clinical Medicine

Background:

• Second-generation H1-antihistamines are first-line for chronic spontaneous urticaria (CSU).
• A significant portion of CSU patients remain symptomatic despite standard treatment.
• Identifying characteristics of patients with high treatment requirements is crucial for optimizing care.

Purpose of the Study:

• To identify clinical and laboratory features associated with high treatment requirements in CSU patients.
• To differentiate characteristics between high-treatment-requirement CSU (HTR-CSU) and non-HTR-CSU.

Main Methods:

• Retrospective cohort study of 6,033 adult CSU patients in a Korean tertiary hospital (2002-2020).
• HTR-CSU defined by simultaneous use of ≥4 H1-antihistamines or omalizumab treatment.
• Comparison of clinical data, medication use, and laboratory findings between HTR-CSU and non-HTR-CSU groups.

Main Results:

• 34.5% of patients were classified as HTR-CSU.
• HTR-CSU patients had longer follow-up durations and higher rates of cholinergic urticaria.
• HTR-CSU was associated with elevated white blood cell counts, neutrophils, total IgE, complement C3/C4, and D-dimer, alongside reduced IgG levels.

Conclusions:

• High-treatment-requirement CSU is linked to longer disease duration and a greater medication burden.
• Distinct laboratory profiles in HTR-CSU, including elevated neutrophils, complement, D-dimer, and IgE, with decreased IgG, suggest unique immunological mechanisms.
• Further research into these mechanisms may lead to more targeted therapies for refractory CSU.