Objective: To estimate annual direct and indirect health care costs in patients with chronic idiopathic urticaria (CIU) managed with conventional therapies., Design: A cost analysis consisting of a survey-guided and retrospective medical record review of direct and indirect health care costs from a societal perspective in patients with CIU., Setting: The Johns Hopkins University allergy and dermatology ambulatory clinics., Participants: Fifty adults with active CIU were recruited in sequential order. Individuals who were taking corticosteroids or other immunosuppressants in the month before enrollment were excluded from the study., Main Outcome Measures: We estimated direct health care costs, which included laboratory, medication, outpatient visit, and emergency department and hospital visit costs. We also estimated indirect costs, which included earnings lost owing to travel to outpatient visits and absences from work owing to CIU-related illness., Results: Patients with CIU consumed a mean (SD) of $2047 ($1483) annually. Because CIU is primarily an outpatient disease, medication costs alone accounted for 62.5% ($1280) of the total annual cost. Indirect costs accounted for 15.7% ($322) of the total costs., Conclusions: High medication costs, followed by total indirect costs, result in the largest economic burden among patients with CIU. High medication costs may place low-income patients at risk for suboptimal treatment and increased burden due to poorly controlled disease. Our estimated total health care costs for CIU are comparable to those of other skin diseases such as vitiligo and bullous disease.