Systemic autoinflammatory disease following COVID-19 mRNA vaccine: a severe and rare clinical presentation

Case 1A 48-year-old woman, without relevant medical records, was referred to our Internal Medicine Unit for persistent elevated fever (over 38.5 C) that had lasted for about 1 month and started the day after she had received the second shot of COVID-19 mRNA vaccine.Upon admission, the patient denied accompanying symptoms and, at physical examination, no significant pathological signs were detected.Blood tests showed only increased C-reactive protein (CRP) levels (Table 1).In the differential diagnostic process, we indeed considered an infective, malignant and/or autoimmune etiology of her febrile status.Multiple blood and urine cultures were performed that resulted sterile as negative for procalcitonin, along with the serology for viruses and autoimmune pattern tests.Total body scan and bone marrow biopsy did not show any pathological signs.She was successfully treated with prednisone 25 mg die ex-juvantibus.After 4 months, she experienced fever relapse during decalage of steroid therapy.