Adhesive capsulitis following COVID-19 vaccination: A case series.

Of the many bizarre complications of administration of the COVID 19 vaccine, adhesive capsulitis is almost unheard-of, although Shoulder Injury following Vaccine Administration (SIRVA), which by definition has symptom onset within 48 hours and is caused by faulty injection technique, has been rarely reported. Nine cases of adhesive capsulitis, five males and four females with a mean age of 48.7 ± 12.7 years, presenting within one month of intramuscular Covishield™ vaccine on the ipsilateral deltoid and fulfilling the standard UK FROST Multicenter Study diagnostic criteria are reported. The mean time interval from vaccination till symptom onset was 12.3 ± 3.1 days, and mean symptom duration was 9.4 ± 2.4 weeks. Conventional treatment with Non-Steroidal Anti Inflammatory Drugs, followed by intra-articular steroid injection coupled with suprascapular nerve steroid block improved the pain score and range of movement in 8 weeks. The exact pathogenesis remains an enigma, although mechanisms such as local spread via deltoid muscle microvasculature, nerves, or SIRVA causing secondary adhesive capsulitis have been hypothesized. While adhesive capsulitis is a very common diagnosis in the physiatric outpatient setting, the possible association with Covishield™ vaccination, the Indian version of the Oxford AstraZeneca recombinant ChAdOx1 nCoV-19 vaccine, is almost absent in existing literature and hence likely to be missed by clinicians, which necessitates this report.