Dermatomyositis in Association With SARS-CoV-2 Infection or COVID-19 Vaccine

New-onset and relapsed dermatomyositis (DM) has been reported following SARS-CoV-2 infection or COVID-19 vaccination. This study aims to show the characteristics of a DM cohort after COVID-19 infection and vaccination.

A retrospective review was performed on patients treated for DM between March 1, 2020, and October 31, 2022. Charts were evaluated for the presence of new-onset DM or relapse of preexisting DM following either SARS-CoV-2 infection or COVID-19 vaccination. Data on symptom onset, timing of vaccination, type of vaccination, and disease characteristics were collected.

Ninety-eight patients treated for DM at our institution in the Division of Rheumatology were included. In total, 12 of 98 patients (12.2%) experienced DM symptoms (either incident or relapse) following either infection or vaccination. Of the 12 patients who developed incident disease or relapse, 7 (58.3%) developed postinfection symptoms, and 8 (66.7%) developed symptoms after vaccination (3 patients had symptoms following both infection and vaccination). The mean onset of symptoms following COVID-19 infection was 3.2 days (median 0.5 days), and mean onset following COVID-19 vaccination was 5.75 days (median 3.5 days). Nine of 12 patients (75%) had a positive myositis-specific antibody, and the remaining 3 (25%) had myositis-associated antibodies. There was no predominant vaccine associated with the development of postvaccination DM symptoms.

This retrospective review revealed a strong temporal relationship between DM symptoms and COVID-19 infection or vaccination in 12.2% of all patients with DM evaluated in our clinic during the pandemic. Additional studies are required to understand the possible pathophysiology behind this association.