Background: Chronic urticaria (CU) requires continuous medication, reducing quality of life and increasing healthcare burden. This study investigated whether bariatric surgery affects CU management through changes in medication use.

Methods: A retrospective cohort study was conducted using Korean HIRA claims data. We included 873 patients with urticaria (ICD-10: L50) who underwent bariatric surgery between 2019–2020. Medications analyzed were oral corticosteroids, injectable corticosteroids, antihistamines, and pseudoephedrine. Prescription trends were assessed over 24 months before and after surgery, excluding the 3 months around surgery to avoid short-term bias. 

Outcomes included prescription rates, monthly prescription days, and corticosteroid-equivalent doses.

Results: Among 873 patients, 571 (65.4%) had no urticaria diagnosis during 2 years post-surgery. Immediately after surgery, prescriptions decreased: oral corticosteroids (–7.5%), injectable corticosteroids (–6.0%), antihistamines (–13.5%), and pseudoephedrine (–12.1%). All reductions were statistically significant. Oral corticosteroids and antihistamines continued to decline steadily over 24 months.

Conclusion: Bariatric surgery was associated with marked reductions in CU-related medication use. These findings suggest that weight loss may improve disease control and reduce the need for long-term pharmacologic treatment in chronic urticaria.