Frozen Shoulder Related to Influenza Vaccine Administration

Shoulder pain is often a transient physical finding after vaccination. We present the case of a 46-year-old woman who presented clinically with frozen shoulder that was progressively worse and temporally related to her yearly influenza vaccination. The patient failed conservative management, and 7 months postvaccination, the patient underwent shoulder manipulation under anesthesia with good results. Vaccination-related shoulder dysfunction after high-deltoid intramuscular penetration and infiltration into the subdeltoid/subacromial bursa can cause a severe local inflammatory response that clinically may present as frozen shoulder. A case report and review of the literature on suspected frozen shoulder injury related to vaccine administration is presented. A greater understanding of the shoulder anatomy and use of the correct intramuscular vaccination administration technique is important to prevent this rare postvaccination complication.