810 - Complex Regional Pain Syndrome (CRPS) following immunization: A systematic review of case reports

Objectives: Vaccines have shown to have the highest efficacy of preventing infectious disease through their ability to induce immunological memory against pathogens. An adverse reaction to a vaccine is an unexpected medical occurrence following immunization. They can occur as a direct result of an immunization or they can be coincidental reactions not directly associated with the immunization process but are temporarily present after vaccine administration. Complex regional pain syndrome (CRPS) is a disease that has undergone much controversy regarding its onset post vaccination. Given the ambiguity surrounding the onset and symptoms of CRPS post-vaccination, it has been suggested that CRPS can manifest as an adverse reaction to immunization. This review aims to evaluate cases of CRPS post-vaccination in an attempt to better understand the manifestation of the disease and its potential association with vaccines.

Design: A systematic review of case reports was conducted employing the PRISMA 2020 guidelines. Outcomes of interest include: type of vaccination, patient age, patient sex, time to symptom onset, and medical history including but not limited to previous autoimmune diseases, psychological illness, physical tissue trauma, and neurological disease.

Results: Initial querying of the five databases yielded 404 articles. Following thorough review of articles, only 14 remained, comprising 18 cases. Studies included cases of CRPS development following tetanus, Hepatitis B, Hepatitis A, Rubella, Influenza, Tetanus-diphtheria, HPV, and COVID-19 vaccine administration.

Conclusions: The limitations of evidence used in this study highlight the need for a greater output of higher level evidence in the form of controlled trials and retrospective studies to help further elucidate the connection between vaccine use and the development of CRPS in patients. At this time, vaccines continue to be safe for global public use.