Disease activity of patients with chronic urticaria receiving COVID-19 vaccines

Background: Cutaneous adverse events after receiving a COVID-19 vaccine were identified. The disease activity of urticaria after a COVID-19 vaccine has never been explored in chronic urticaria patients. Objectives: To evaluate disease activity of chronic urticaria after receiving a COVID-19 vaccine. Methods: A prospective cross-sectional study was conducted in chronic urticaria patients aged 18 or above who visited Siriraj Hospital between July and September 2021, and received the first and second dose of COVID-19 vaccine. The status prior to vaccination, including disease activity, disease control and disease severity was assessed by a urticaria activity score over seven days, urticaria control test, and modified medication score. The disease activity after vaccination was recorded. Results: A total of 130 patients with a mean age of 45.9 ± 14.7 were enrolled in this study. Adenoviral and inactivated vaccines were administered to 85 (65.4%) and 45 patients (34.6%), respectively. Exacerbation was reported in 20 cases (15.4%) after the first dose and 17 cases (13.1%) after the second dose. Nine patients (45%) reported exacerbation after both the first and second dose. The majority of patients only had wheal, while three patients reported wheal with angioedema. No anaphylaxis was reported. Factor predicting exacerbation was concurrent thyroid disease (aRR 2.78, p < 0.01). Conclusion: Approximately 15% of chronic urticaria patients reported exacerbation after receiving a COVID-19 vaccination. No serious events were observed. Chronic urticaria patients should be vaccinated against COVID-19 after a discussion of the risk of disease flare-up.