With the ongoing pandemic due to coronavirus disease (COVID-19), vaccination is an important intervention in preventing the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Messenger RNA (mRNA) vaccines from Pfizer™ and Moderna™ are the first to market in the United States, and while cutaneous adverse events have been reported in clinical trials for both of these vaccines, they have not been well characterized in the literature.
A 41-year-old woman with history of varicella infection in childhood presented with a 5-day history of skin pain and rash. Her medical history included migraine. She was not taking any medications. 8 days prior, the patient underwent vaccination for COVID-19 (Moderna™). The patient noted that for 2-3 days after vaccination she experienced fatigue and left arm soreness around the injection site. She also reported diarrhea at 24 hours post-vaccination. Two days post-vaccine the patient began to experience skin pain affecting the left lower back. Over the ensuing days she noted the development of a vesicular rash at this site.
Physical examination revealed a cluster of pink to red erythematous urticarial appearing papules and plaques with overlying clustered vesicles. Vesicular fluid was collected for VZV DNA PCR which yielded a positive result. Upon follow up, the patient reported that her symptoms and rash subsided without treatment over the following week.
Herpes zoster (Hz), characteristically presents with unilateral radicular pain and vesicular rash, usually localized to a single dermatome region.1,2 Hz is caused by reactivation of the varicella-zoster virus (VZV) following an earlier infection and ensuing latency period.2,3 VZV is a ubiquitous alphaherpesvirus, which targets T lymphocytes, epithelial cells and ganglia.4 Before licensure of the pediatric varicella vaccine, an estimated 96% of people in the US experienced chicken pox by age 20.5 VZV infection begins in somatic cells, such as epithelia, and subsequently spreads through the neurons, moving in the retrograde direction toward cell bodies, where they establish a lifelong latency within the dorsal root or trigeminal ganglia.6,7 Reactivation of the virus from its latent state leads to assembly and dissemination of viral particles in the anterograde direction, manifesting the characteristic vesicular rash.6,8 Precise immune mechanisms that limit viral reactivation are still not well understood.5 Nevertheless, reactivation is most commonly attributed to diminished cellular immunity due to advanced age and/or immunosuppression.9 More than 50% of Hz cases occur in individuals over 60 years of age.2,10 Additionally, altered cell-mediated immunity, neoplastic diseases, immunosuppressive drugs, organ-transplant recipient status, and human immunodeficiency virus (HIV) increase individuals’ risk for developing Hz.11,12
The SARS-CoV-2 vaccine developed by Moderna™ and the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases (NIAID), within the National Institutes of Health (NIH), otherwise titled mRNA-1273, is an FDA-emergency authorized lipid-nanoparticle encapsulated mRNA vaccine, which expresses the prefusion-stabilized glycoprotein, administered in two doses 28 days apart. In the latest Phase 3 clinical trials, the vaccine demonstrated 94.1% efficacy in preventing symptomatic COVID-19 and also demonstrated efficacy in preventing severe COVID-19 disease.13 Overall, local reactions to vaccinations were mild. Moderate-to-severe systemic side effects such as fatigue,