Do regional geography and race influence management of chronic spontaneous urticaria?

Chronic spontaneous urticaria is defined as migratory evanescent pruritic blanching wheals that occur with variable frequency for 6 weeks or more, with or without accompanying angioedema. This condition affects approximately 0.1% to 1.4% of persons worldwide. Second-generation H1 antihistamines are the mainstay of management, with refractory cases often managed with an array of options, including H2 antihistamines, leukotriene receptor antagonists, glucocorticosteroids, immunosuppressive agents, and omalizumab. However, the degree of practice variation as to what treatments are prescribed is poorly understood, given that clinical care could be driven by patient preferences or lack of clarity as to best practices for refractory cases. We conducted a small, exploratory study of the role of race, ethnicity, and regional geographic distance to specialist care on chronic spontaneous urticaria prescribing practices. A small-area geographic variation in chronic spontaneous urticaria management in a large Chicago-area health care system was identified. Rates of omalizumab use varied by patient zip code, with more omalizumab prescriptions being associated with zip codes closer to the main office of an academic medical center-affiliated allergist-immunologist practice. Higher rates of omalizumab use were associated with White race in regional and patient-level analyses, though the reasons for this race-based finding are not clear.