Dermatomyositis Flare-Up Following the SARS-CoV-2 Vaccine: A Case Report and Literature Review.

Dermatomyositis is a rare auto-immune inflammatory myopathy of unknown etiology. Several environmental factors, including vaccines, have been identified as potential triggers in genetically susceptible individuals. Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, the development of vaccines (mRNA and vector-based) has been the most effective tool in reducing the incidence, hospitalization rates, and mortality of COVID-19. However, among individuals with immune dysregulation and auto-immune conditions, unique challenges may arise with immune stimulation. We present a case of a dermatomyositis flare-up following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. A 40-year-old Hispanic female presented to the emergency department with shortness of breath, muscle pain and weakness, and skin rash for two days. She had been recently diagnosed with dermatomyositis six months prior based on clinical presentation, laboratory investigations, and characteristic muscle biopsy findings. She had been on treatment with mycophenolate mofetil, prednisone, and hydroxychloroquine since. She reported receiving the second dose of the BNT162b2 COVID-19 vaccine one day prior to the onset of symptoms. Physical examination revealed erythematous plaques over her cheeks, upper chest, and arms, in addition to Gottron papules on her hands. She had reduced proximal muscle strength and scattered dry crackles bilaterally on lung auscultation. Her laboratory investigations were remarkable for elevated erythrocyte sedimentation rate, C-reactive peptide, creatinine kinase, and troponin T. The SARS- CoV-2 PCR test was negative. CT scan of the chest showed evidence of pneumonitis. A diagnosis of the dermatomyositis flare-up potentially secondary to the SARS-CoV-2 BNT162b2 vaccine was established. The patient was admitted and treated with pulse steroids and intravenous immunoglobulin. She responded well to therapy and was discharged home four days later. There have been several reports of a new onset of dermatomyositis following the SARS-CoV-2 vaccine which highlights the need for further large-scale studies to estimate the prevalence of such adverse effects. The benefits of the SARS-CoV-2 vaccine outweigh the risks even among patients with auto-immune and rheumatologic conditions; however, it is important for clinicians to recognize the possibility of occurrence of such events in order to manage patients appropriately.