Mortality in adult patients with chronic spontaneous urticaria: A real world cohort study.

Background: Chronic spontaneous urticaria (CSU), a common and debilitating disease, is widely held not to be life-limiting, but the mortality of CSU has not been investigated.

Objective: To assess all-cause mortality in CSU patients, risk for comorbidities that are leading causes of death and impact of guideline-recommended urticaria treatments on mortality rates.

Methods: This is a retrospective population-based cohort study of electronic health records of 272,190 adult CSU patients and 12,728,913 non-urticaria controls from the US Collaborative TriNetx Analytics Network.

Results: The study included 264,680 propensity score-matched patients with CSU (mean [SD] age, 47.5 [19.8] years; 71.5% female) and a corresponding number of non-urticaria controls. Patients with CSU had a higher three-month, one-year, and five-year all-cause mortality (hazard ratio, HR=2.09, 95% CI=1.97-2.21, HR=1.77, 95% CI=1.71-1.83, and HR=1.69, 95% CI=1.65-1.73, respectively; all p<0.0001). As compared to non-CSU controls, CSU patients exhibited higher risk and rates of the leading causes of death in the US including suicidal ideations/suicide attempts (HR=3.14, 95% CI=3.00-3.28), and malignant neoplasms (HR=2.09, 95% CI=2.02-2.16). The risk of mortality in CSU appeared to be more pronounced in White and younger patients. All-cause mortality rates at 5 years were significantly lower in CSU patients treated with second generation H1-antihistamines versus untreated patients (1.0% vs. 2.3%, HR=1.84, p<0.0001) and omalizumab-treated patients versus antihistamine-treated patients (0.7% vs. 2.6%, HR=3.99, p=0.003).

Conclusion: CSU is associated with increased mortality likely due to comorbidities, especially suicide, and effective CSU treatment may reduce mortality. These findings should be investigated in additional studies, also in other populations.