RT Journal Article SR Electronic T1 Streptococcus gordonii septic arthritis of the glenohumeral joint following deltoid intramuscular vaccination JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e243066 DO 10.1136/bcr-2021-243066 VO 14 IS 5 A1 Robert Costigan Flowers A1 Beatriz Rivera Rodriguez A1 Kelly Corbitt YR 2021 UL http://casereports.bmj.com/content/14/5/e243066.abstract AB A 68-year-old woman presented for left shoulder pain, decreased range of motion (ROM) and fever 7 days following COVID-19 vaccination. Investigations showed a tender left deltoid mass, decreased shoulder ROM and elevated inflammatory markers. MRI demonstrated a large glenohumeral effusion with synovitis, and arthrocentesis confirmed septic arthritis (SA). She required subtotal bursectomy. Intraoperative joint cultures grew Streptococcus gordonii. She completed 6 weeks of antibiotics and is undergoing physical therapy for post-infectious adhesive capsulitis. SA is most commonly due to Staphylococcus aureus and β-haemolytic streptococci, and rarely due to viridans group streptococci including S. gordonii. To avoid inadvertent injection into the glenohumeral joint, vaccination should be performed posteriorly and inferiorly into the deltoid musculature. Progressive pain, fever or decreased passive ROM following vaccination should raise concern for SA. Given its rarity, however, concern for secondary SA should not affect the general population’s consideration for vaccination.