Onset of dermatomyositis in close association with COVID-19—a first case reported

Anti-NXP2 antibody-positive dermatomyositis developed after COVID-19 manifesting as type I interferonopathy

“…The manifestation of COVID-19 varied from pyrexia alone to mild respiratory symptoms, and neither was severe enough to require mechanical ventilation. The four cases demonstrated some characteristic features of DM, such as dermatological findings (observed in the present and other two cases [ 2 , 3 ]); myositis-specific autoantibodies, including anti-NXP2 antibody (detected in the present case), anti- SUMO-1 activating enzyme A antibody [ 1 ] and anti-Mi-2 antibody [ 2 ]; and histologically positive MxA staining (observed in the present case). All cases that received intravenous methylprednisolone showed an early favourable response.…”

“…We reviewed four cases of COVID-19-associated DM, including the present case and those reported until July 2021 [ 1–3 ]. Among these, only one case had myopathic symptoms simultaneously with COVID-19 [ 1 ], whereas the present and other two cases [ 2 , 3 ] presented cutaneous manifestation simultaneously to 1 month after COVID-19. The manifestation of COVID-19 varied from pyrexia alone to mild respiratory symptoms, and neither was severe enough to require mechanical ventilation.…”

Anti-MDA5 Antibody Linking COVID-19, Type I Interferon, and Autoimmunity: A Case Report and Systematic Literature Review

“…Eleven cases of inflammatory myositis temporally related to COVID-19 have been reported (20)(21)(22)(23)(24)(25)(26)(27); the main features are illustrated in Table 1. In nine patients, new-onset inflammatory myositis followed SARS-CoV-2 infection; two cases of disease relapse following COVID-19 have been reported: one at pediatric age (22) (in a child who experienced a skin-only relapse of juvenile DM) and one in the adult setting (20) (in a patient positive for both anti-Mi-2 and anti-PM/Scl antibodies).…”

“…Two patients ( 20 , 23 ) tested positive for anti-MDA5 antibodies: one of them (also positive for anti-Ro52 antibodies) underwent fatal macrophage activation syndrome ( 23 ), the other (also positive for anti-SAE-1 antibodies) died due to pneumonia ( 20 ). Two patients were positive for anti-Mi-2 antibodies: one of them was diagnosed new-onset DM ( 25 ), the other (also positive for anti-PM/Scl antibodies) experienced disease relapse ( 20 ). Moreover, one case of anti-NXP2 DM was described ( 27 ).…”

Exclude differentials before attributing post-COVID fatigue to myopathy

“…No follow-up data, particularly no follow-up EMGs, were provided. There are indications that SARS-CoV-2 may be complicated by dermatomyositis ( Borges et al, 2021 ). We should be told how dermatomyositis was excluded in the one patient with elevated ESR.…”