Anti-MDA5 dermatomyositis after COVID-19 vaccination: a case-based review.

Anti-MDA5 (Melanoma differentiation-associated protein 5) myositis is a rare subtype of dermatomyositis (DM) characterized by distinct ulcerative, erythematous cutaneous lesions and a high risk of rapidly progressive interstitial lung disease (RP-ILD). It has been shown that SARS-CoV-2 (COVID-19) replicates rapidly in lung and skin epithelial cells, which is sensed by the cytosolic RNA-sensor MDA5. MDA5 then triggers type 1 interferon (IFN) production, and thus downstream inflammatory mediators (EMBO J 40(15):e107826, 2021); (J Virol, 2021, https://doi.org/10.1128/JVI.00862-21 ); (Cell Rep 34(2):108628, 2021); (Sci Rep 11(1):13638, 2021); (Trends Microbiol 27(1):75-85, 2019). It has also been shown that MDA5 is triggered by the mRNA COVID-19 vaccine with resultant activated dendritic cells (Nat Rev Immunol 21(4):195-197, 2021). Our literature review identified one reported case of MDA5-DM from the COVID-19 vaccine (Chest J, 2021, https://doi.org/10.1016/j.chest.2021.07.646 ). We present six additional cases of MDA5-DM that developed shortly after the administration of different kinds of COVID-19 vaccines. A review of other similar cases of myositis developing from the COVID-19 vaccine was also done. We aim to explore and discuss the evidence around recent speculations of a possible relation of MDA5-DM to COVID-19 infection and vaccine. The importance of vaccination during a worldwide pandemic should be maintained and our findings are not intended to discourage individuals from receiving the COVID-19 vaccine.

Life-threatening complications of Henoch-Schönlein purpura: diffuse alveolar haemorrhage, venous thrombosis and bowel ischaemia.

Henoch-Schönlein purpura (HSP) is a common systemic vasculitis occurring in children. Making a diagnosis of HSP is often straightforward, managing its complications can be difficult. Diffuse alveolar haemorrhage (DAH), bowel ischaemia and venous thrombosis are rare complications of this disorder. We present a case of a 15-year-old teenage girl presenting with typical purpuric rash of HSP, developed DAH, bowel ischaemia and venous thrombosis. She was successfully treated with pulse methylprednisolone, intravenous Ig and intravenous cyclophosphamide.

Macrophage activation syndrome as an initial presentation of systemic lupus erythematosus with sensorineural hearing loss in a young male patient.

An 18-year-old male adolescent presented with prolonged high spiking temperature, photosensitive rash, oral ulcers and reduced hearing bilaterally of recent onset. Examination revealed malar rash, vasculitis rash over bilateral palms and soles, oral and buccal ulcers, palpable posterior auricular and inguinal lymph nodes, and reduced hearing bilaterally. His further investigations noted pancytopaenia, elevated transaminases, hyperferritinaemia, low C3 and C4 levels, positive antinuclear antibody, double-stranded DNA and direct Coombs test, while bone marrow aspiration revealed active phagocytic activity suggestive of hemophagocytic syndrome. We made a diagnosis of systemic lupus erythematosus with macrophage activation syndrome. We treated him with pulse intravenous methylprednisolone and his condition improved drastically. Temperature resolved on the next day after intravenous methylprednisolone; bilateral sensorineural hearing loss improved to near-normal hearing after treatment. He remained well during follow-up with a tapering dose of prednisolone.