Polymyalgia Rheumatica Evolved into RS3PE Syndrome. What is the Culprit: Idiopathic or Secondary, Following mRNA-Based COVID-19 Vaccines? A Case Report and Brief Review of the Literature

We describe the clinical case of a 74-year-old male patient who received second Comirnaty/Pfizer anti-COVID-19 vaccine dose. After 3 weeks he showed signs polymyalgia rheumatica. The history included mild chronic normocytic normochromic anemia and hypogammaglobulinemia, osteoarthritis disease, livedo reticularis, hypercholesterolemia, arterial hypertension. Despite prolonged treatment with NSAIDs dexamethasone, disease evolved into remitting seronegative symmetrical synovitis pitting edema (RS3PE) syndrome. Neoplastic diseases associated collagen were excluded. picture recurred, soon after, booster dose Spikevax/Moderna vaccine. inflammatory indices high, radiographs hands free erosions, ultrasound investigations revealed bursitis shoulders, knee synovitis, marked subcutaneous lower limbs, hydrocele, bilateral Baker's cyst in popliteal cavity, hematoma calf. picture, markedly improved, oral prednisolone was stabilized association hydroxychloroquine. finding persistent hypomagnesemia related to intake esomeprazole. reports rheumatological reactions international databases rare cases RS3PE <u>s</u>yndrome following COVID-19 described literature are considered.