Global prevalence and clinical manifestations of cutaneous adverse reactions following COVID-19 vaccination: A systematic review and meta-analysis.

Although vaccination is widely accepted as an effective method of preventing and controlling the COVID-19 pandemic, many people are concerned about possible cutaneous side-effects, which can delay or prevent them from being vaccinated. The objectives of this systematic review were to assess the global prevalence and clinical manifestations of cutaneous adverse reactions following COVID-19 vaccination. PubMed and Scopus databases were searched for articles published from 1 January 2019 to 31 December 2021, and reference lists for each selected article were screened. Case reports, case series, observational studies and randomized controlled trials that provided information on cutaneous adverse reactions following COVID-19 vaccines were included. A total of 300 studies were included in a systematic review of which 32 studies with 946 366 participants were included in the meta-analysis. The pooled prevalence of cutaneous manifestations following COVID-19 vaccination was 3.8% (95% CI, 2.7%-5.3%). COVID-19 vaccines based on the mRNA platform had a higher prevalence than other platforms at 6.9% (95% CI, 3.8%-12.3%). Various cutaneous manifestations have been reported from injection site reactions, which were the most common (72.16%) to uncommon adverse reactions such as delayed inflammatory reactions to tissue filler (0.07%) and flares of pre-existing dermatoses (0.07%). Severe cutaneous reactions such as anaphylaxis have also been reported, but in rare cases (0.05%). In conclusion, cutaneous adverse reactions are common, especially in those receiving mRNA vaccines. Most reactions are mild and are not contraindications to subsequent vaccination except for anaphylaxis, which rarely occurs. COVID-19 vaccination may also be associated with flares of pre-existing dermatoses and delayed inflammatory reactions to tissue filler. Patients with a history of allergies, pre-existing skin conditions or scheduled for filler injections should receive additional precounselling and monitoring. A better understanding of potential side-effects may strengthen public confidence in those wary of new vaccine technologies.

Acute urticaria alone after CoronaVac COVID-19 vaccination should not be a contraindication for revaccination.

Patients who develop an immediate allergic reaction within the first 4 h of COVID-19 vaccine injection are recommended not to receive the same vaccine again. This recommendation mainly focuses on the mRNA and adenoviral vector COVID-19 vaccines, but data for whole virus vaccines are unknown. We report seven patients who developed an immediate reaction within 4 h (six had generalized urticaria, one had localized urticaria) after the first vaccination with CoronaVac, the inactivated SARS-CoV-2 vaccine. The results of skin tests and basophil activation tests suggested that spike peptides play a role in exacerbating urticaria in some patients. However, all subjects who developed urticaria within 4 h after CoronaVac vaccination were successfully revaccinated without graded challenge, although recurrent urticaria was common. This preliminary result indicates that acute urticaria alone should not be a contraindication for the second dose of CoronaVac if the supply of alternative vaccines is limited.