Urticaria Following COVID-19 Booster Vaccination: Case Series and Review

Abstract

Background: Over 610 million doses of the COVID-19 vaccine have been administered since late 2020, and adverse events associated with these vaccinations have been widely reported. Less commonly reported are cutaneous complications associated with COVID-19 vaccination, which are rare but troublesome.

Case Series: We report 7 cases of delayed-onset urticaria following Moderna Covid-19 booster vaccination. Patients ranged from aged 20-46, and no patients had a history of previous urticaria. Average day of onset following the booster vaccination was 10.9, with 6 of the 7 patients experiencing chronic urticaria. No patients experienced anaphylaxis.  All patients were managed with oral antihistamines in an outpatient setting.

Discussion: Unlike previously documented reactions following COVID-19 vaccination, we report on widespread and long-lasting dermatographic urticarial eruptions that presented an average of 10.9 days after receipt of the booster vaccination. The pathophysiology underlying these eruptions is difficult to elucidate given the lack of connection to atopy, autoimmune conditions, or systemic illness; however, we propose 3 possible mechanisms involving the prostaglandin pathway, IL-2 upregulation, and ACE2 receptors. Despite the benign nature and outpatient treatment of chronic urticarial eruptions, these eruptions distress patients and impact quality of life. Fortunately, no systemic reactions or respiratory system involvement occurred in any of our patients, and outpatient antihistamine therapy provided adequate symptomatic relief to our patients. Given the delayed reaction time and lack of systemic involvement, there is likely minimal risk in receiving additional COVID-19 booster following post-vaccination urticaria.