COVID-19 vaccines: What dermatologists should know?

Do we miss rare adverse events induced by COVID-19 vaccination?

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused many complications, the invention of coronavirus disease 2019 (COVID-19) vaccines has also brought about several adverse events, from common side effects to unexpected and rare ones. Common vaccine-related adverse reactions manifest locally or systematically following any vaccine, including COVID-19 vaccines. Specific side effects, known as adverse events of particular interest (AESI), are unusual and need more evaluation. Here, we discuss some of the most critical rare adverse events of COVID-19 vaccines.

Cutaneous Reactions to COVID-19 Vaccines in a Monocentric Study: A Case Series

After coronavirus disease 2019 (COVID-19) caused a global pandemic, vaccines were rapidly developed to control the spread of the virus. Although they were effective in most of the cases at protecting people from becoming seriously ill and being hospitalized, they showed side effects, too. Among other adverse vaccine reactions, cutaneous eruptions following SARS-CoV-2 have been described in the literature, but they are not well-characterized yet. We described the morphology and timing of the spectrum of cutaneous reactions following most of the COVID-19 vaccines available in Italy, which were observed in outpatients referred to our non-invasive diagnostic clinic. Most of these reactions appeared after the second or third COVID-19 vaccine dose (most of them after mRNA COVID-19 vaccines). Our data support that cutaneous reactions to COVID-19 vaccination are generally self-limited; in addition, history of allergic reaction to a specific food, medicine or vaccine should not discourage vaccination in the general population, although patients with immune dysregulation should be accurately selected and monitored. Further research is necessary to better assess the true prevalence and preventive measures of skin reactions to COVID-19 vaccination.

A Comparative Review on Mucocutaneous Reactions Caused by Covid-19 Infection versus Covid-19 Vaccination

IMPORTANCE

The prevalence and severity of mucocutaneous manifestations in Covid-19 infection are generally higher than those reported in Covid vaccines. Therefore, comparing the mucocutaneous reactions of the Covid-19 infection and vaccination is necessary to enhance our knowledge about such reactions and guide us to evaluate the risk of infection or vaccination.

OBSERVATION

A thorough literature search was conducted on PubMed, Google Scholar, and EBSCO (LISTA), and 2,069 articles were downloaded. After screening, 11 studies remained for the final review. The literature review revealed that the prevalence and severity of post-vaccine mucocutaneous adverse reactions have been less common compred to Covid-19 infection. Post-vaccine adverse reactions primarily occurred after the first dose administration and such reactions were manageable with antihistamines and corticosteroids administration.

CONCLUSIONS AND RELEVANCE

The current comparative analysis highlights the frequency and potential severity of mucocutaneous reactions due to Covid-19 infection and Covid-19 vaccination. It also affirmed that potentially critical (serious) mucocutaneous reactions are more likely to occur in Covid-19 infection compared to Covid vaccination. Moreover, post-vaccine reactions predominantly happened after the first dose and were reported to be non-life-threatening, self-manageable, and with a lower incidence of potentially critical events. It was also concluded that the incidence of mucocutaneous reactions decreased in the following doses. Hence, given the low rate of such reactions following Covid-19 vaccination, vaccines have a lower risk of mucocutaneous reactions occurrence than Covid-19 infection. Further, due to the limited number of studies, we recommend that large-scale trials evaluate such reactions comparing various types of Covid-19 vaccines in healthy individuals and those with autoimmune skin disorders.

COVID-19 vaccines: What dermatologists should know?

As COVID‐19 vaccination has started worldwide to control this pandemic, dermatologists may face various challenges with these new vaccines. In this manuscript, we review different types of available COVID‐19 vaccines and their various production platforms. Vaccination considerations in patients with skin diseases, especially those using immunomodulatory drugs will be presented. Finally, adverse cutaneous reactions of COVID‐19 vaccines will be reviewed.