Low risk of urticaria exacerbation following COVID-19 vaccination

Reactions 1971, p9 - 26 Aug 2023 The risk of urticaria exacerbation in patients with chronic urticaria (CU) receiving COVID-19 vaccination is low. This is the main finding of a study that used a questionnaire to evaluate CU exacerbations and other adverse events, including severe allergic reactions, in patients with CU receiving COVID-19 vaccination. The study, COVAC-CU, used data from CU patients who received COVID-19 vaccinations at 50 Urticaria Centers for Reference and Excellence (UCAREs) in 26 countries. The study was conducted over the period from August 2021 through March 2022. The analysis included data from 2769 patients with CU, of whom most (90%) received at least two COVID-19 vaccine doses. The rate of vaccine-related CU exacerbation was low (9%). This rate is "markedly lower than the rate of CU patients who experience exacerbation of CU after COVID-19," note the researchers. CU exacerbation occurred in 8% of patients after the first dose, in 9.6% after the second dose and in 11% after the third dose. Patients who received adenovirus viral vector (AVV) vaccines had a significantly higher rate of CU exacerbation after the first dose as compared to patients who received inactivated viral vaccines or mRNA vaccines. Risk factors that increased the risk for vaccine-related CU exacerbation included female gender, disease duration < 24 months, having chronic spontaneous versus inducible urticaria, receipt of an AVV vaccine, NSAID/aspirin intolerance and having concerns about getting vaccinated. In contrast, patients receiving omalizumab and those of Latino/Hispanic ethnicity had a lower risk of CU...