Post-vaccination frozen shoulder syndrome. Report of 3 cases.

The cause of frozen shoulder syndrome is unknown in most cases, although it can be preceded by minor trauma. Here, we report 3 patients with severe frozen shoulder after an intramuscular vaccination in the deltoid muscle. A distention arthrography resulted in good pain relief and improved the mobility. Frozen shoulder syndrome can be a severe manifestation of vaccination-related shoulder dysfunction. Correct intramuscular administration is crucial to prevent post-vaccination frozen shoulder and on the other hand, physicians' awareness is needed to recognize this feature early on.