Calcific tendinitis of the shoulder induced by an mRNA vaccine for COVID-19: A case report.

Coronavirus disease 2019 (COVID-19) vaccines have been widely used and have been shown to be effective in combating the pandemic. However, various side effects have been reported following vaccination. For instance, a condition called 'shoulder injury related to vaccine administration' (SIRVA) is characterized by shoulder pain and limited range of motion after intramuscular injection of a vaccine into the deltoid muscle of the shoulder. Despite an increase in SIRVA cases, the exact incidence of the disease is unclear, and there are a few reports of SIRVA about the COVID-19 vaccine. Here, we report a rare case of an 83-year-old woman who was diagnosed with calcification in her left shoulder 1 year ago and developed calcific tendinitis after receiving an mRNA vaccine for COVID-19 (Pfizer-BioNTech). Radiographs showed calcification of the supraspinatus tendon, and magnetic resonance images showed continuous inflammatory findings from the subdeltoid bursa to the subacromial bursa. We treated the patient with celecoxib and acetaminophen, and she recovered after about 2 months. In order to prevent SIRVA, the presence of shoulder joint disease should be carefully asked during a pre-vaccination assessment. The puncture point should be chosen with the median point of the deltoid muscle or the anterior-posterior axillary line as landmarks because the more cephalad the puncture position, the greater the chance of causing SIRVA.