Post-COVID-19 vaccination arm pain diagnosed as complex regional pain syndrome: A case report.

As the vaccination efforts against the coronavirus disease-2019 (COVID-19) continue, more patients are likely to present with complications related to COVID-19 vaccination. We describe the first reported case of complex regional pain syndrome (CRPS), involving the upper extremities, that occurred after COVID-19 vaccination. The patient presented with acute-onset severe arm pain and swelling following vaccine administration. Based on the clinical, electrodiagnostic, and radionuclide three-phase bone scan findings, the patient was diagnosed with postvaccination CRPS. The COVID-19 vaccine possibly elicited an immune-mediated inflammatory response to the injected antigen in the patient, who was predisposed to CRPS due to inflammatory immunity. The COVID-19 vaccine elicited an immune-mediated inflammatory response to the injected antigen, resulting in CRPS following COVID-19 vaccination.

Neuralgic Amyotrophy with Concomitant Hereditary Neuropathy with Liability to Pressure Palsy as a Cause of Dropped Shoulder in a Child after Human Papillomavirus Vaccination: A Case Report.

Hereditary neuropathy with liability to pressure palsy (HNPP) makes nerves increasingly susceptible to mechanical pressure at entrapment sites. Neuralgic amyotrophy (NA) can cause sudden regional weakness following events to which the patient is immunologically predisposed, such as vaccination. However, NA related to human papilloma virus (HPV) vaccination is seldom reported. We describe the case of a child with NA as the cause of a dropped shoulder following the administration of the HPV vaccine. Underlying asymptomatic HNPP was confirmed in this patient based on the electrodiagnostic findings and genetic analysis. We speculate that HPV vaccination elicited an immune-mediated inflammatory response, resulting in NA. Our patient with pre-existing HNPP might be vulnerable to the occurrence of an immune-mediated NA, which caused the dropped shoulder.