Cost, utilization, and patterns of medication use associated with chronic idiopathic urticaria.

BACKGROUND The literature on chronic idiopathic urticaria (CIU) lacks large-scale population-based studies. OBJECTIVE To characterize an insured population with CIU, including their demographic characteristics and comorbidities. METHODS We conducted a cross-sectional analysis using insurance claims. We included patients with 1 outpatient claim with an International Classification of Diseases, 9(th)Edition, Clinical Modification (ICD-9-CM) code for idiopathic, other specified, or unspecified urticaria (ICD-9-CM 708.1, 708.8, or 708.9) and either (1) another of these claims 6 or more weeks later; (2) a claim for angioedema (ICD-9-CM 995.1) 6 or more weeks from the urticaria diagnosis; or (3) overlapping claims for 2 prescription medications commonly used for CIU. RESULTS We identified 6,019 patients who had claims consistent with CIU. The mean age was 36 years. Fifty-six percent of patients had primary care physicians as their usual source of care, 14% had allergists, and 5% had dermatologists. Allergic rhinitis was diagnosed in 48%, asthma in 21%, other allergy in 19%, and atopic dermatitis in 8%. Sixty-seven percent of patients used prescription antihistamines, 54% used oral corticosteroids (OCSs), 24% used montelukast, and 9% used oral doxepin. Antihistamine users received a mean of 152 days of prescription antihistamines, OCS users 30 days of OCSs, montelukast users 190 days of montelukast, and oral doxepin users 94 days of doxepin. CONCLUSIONS Primary care physicians managed most patients with CIU. Antihistamines were the most common treatment for CIU, although OCSs were frequently prescribed. Thirty days of OCS supply among users may represent multiple steroid bursts each year. Given the known risks of OCSs, identifying other CIU treatments with more favorable safety profiles may be beneficial.