Background: Background: Anti-Melanoma Differentiation-Associated gene 5 (MDA-5) Dermatomyositis (MDA5, DM) is a rare systemic autoimmune disease, characteristically associated with Rapidly Progressive Interstitial Lung Disease (RP-ILD) and cutaneous manifestations. Anti-MDA5 dermatomyositis may develop in genetically predisposed subjects after environmental exposure such as vaccines, infections and neoplasms (1). Myalgia is one of the main symptoms related to SARS-COV2 infection and sometimes may occurs after COVID-19 vaccine administration (2). However, only few cases have reported the occurrence of severe inflammatory myopathies after COVID19 vaccine administration (3)

Objectives: To describe a case of Anti-MDA5 Dermatomyositis occurred after BNT162b2 vaccine administration

Methods: This is a case of a 44 year-old-patient affected by Anti-MDA5 Dermatomyositis occurred after BNT162b2 vaccination referred at the Center for Rheumatic Diseases in Venice, Italy

Results: A 44 year-old-woman presented to the Center for Rheumatic Diseases in Venice, suffering from a cutaneus rash on her face, upper limbs, décolleté, gluteus and lower limbs occurred two days after the first dose BNT162b2 vaccination ( Figure 1 ). A few days after the second dose of the vaccine the rash got worse and myalgias, strength deficiency and fatigue occurred. Elevated inflammatory and myocytolysis parameters were detected ( Table 1 ). After chest HRCT a mild ILD was diagnosed. Muscle edema was detected with whole-body short tau inversion recovery (STIR)-MRI ( Figure 1 ).The Skyn biopsy showed features of dermatomyositis with perivascular inflammatory infiltrates. 1 mg/Kg/die of prednisone was administered and then cyclosporine 3mg/kg/die was associated with clinical benefit.

Conclusion: In rare cases COVID-19 vaccination could induce inflammatory myopathies (3). COVID-19 vaccine administration may have acted as a trigger for the myopathy driven by an autoimmune-mechanism. In such cases, it could be useful to investigate inflammatory myopathies, requiring blood tests (e.g. myocytolysis indices and anti myositis antibodies) and medical instrumental insights, in patients affected by skin manifestation and muscle pain occurred after vaccine administration. Although the association between vaccination and inflammatory myopathies is presumptive, the temporal proximity of the BNT162b2 vaccine to the onset of the signs and symptoms related to the inflammatory miopathies may suggest a possible relationship between these two events. To the best of our knowledge this is the first case of Anti-MDA5 Dermatomyositis occurred after BNT162b2 vaccination.

REFERENCES:

[1]Mehta P, Machado P.m, Gupta L. Understanding and managing anti-MDA 5 dermatomyositis, including potential COVID-19 mimicry. Rheumatol Int 2021 Jun;41(6):1021-1036

[2]Beatty A.L, Peyser N.D, Butcher X.E, Cocohoba J.M, Lin F, Olgin J.E, Pletcher M.J, Marcus G.M. Vaccine side-effects and SARS-CoV-2 infection after vaccination in users of the COVID Symptom Study app in the UK: a prospective observational study Lancet Infect Dis 2021; 21: 939–49

[3]Maramattom B.V, Philips G, Thoas J, Santhamma Nair S.G. Inflammatory myositis after ChAdOx1 vaccination. The Lancet Rheumatology Volume 3, ISSU 11, e747-e749, November 01.2021

Disclosure of Interests: None declared