Document Type

Conference Proceeding

Publication Date


Publication Title

J Allergy Clin Immunol


Rationale: Adverse reactions to COVID-19 vaccinations have garnered significant attention from both the public and medical community. Delayed onset urticaria has been described as an adverse reaction to COVID-19 vaccination, but this phenotype has not been fully characterized thus specific evaluation and treatment strategies have not been developed.

Methods: We conducted a retrospective chart review of patients presenting for evaluation of urticaria (acute or chronic) to the University of Washington Allergy Clinics between 12/14/2020 and 12/14/2021. Records were reviewed for development of delayed onset, persistent urticaria occurring following receipt of a COVID-19 vaccination or a history of chronic spontaneous urticaria that worsened after COVID-19 vaccination. Demographic and clinical data including age, sex, co-morbid conditions, treatments attempted, and treatment response was obtained.

Results: 22 total patients were determined to have urticaria thought to be attributed to Pfizer and Moderna COVID-19 vaccinations. Six of the 22 (27%) had pre-existing chronic spontaneous urticaria (CSU) which worsened notably after vaccination, and 16 (73%) had novel development of delayed urticaria following vaccination. Patients received a range of treatments including H1-antihistamines, H2-antihistamines, leukotriene inhibitors, oral steroids, omalizumab, cyclosporine, and acupuncture. The majority of patients had improvement or resolution while a minority had worsening urticaria despite treatments at the time of evaluation.

Conclusions: COVID-19 vaccinations may result in the development of chronic urticaria in select patients and may worsen control of urticaria in some patients with previously diagnosed chronic urticaria. Additional studies are needed to characterize these patients and determine optimal management strategies.





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