Revaccination following suspected vaccine-triggered hypersensitivity reactions: experience of a tertiary care centre

Suspected hypersensitivity reactions (HRs) associated with vaccines are frequently reported, but confirmed cases of vaccine-triggered HRs are rare. Suspected HRs should be distinguished from actual HRs. The aims of this study are to identify the rate of actual vaccine-triggered hypersensitivity in patients who were referred to the paediatric allergy clinic due to a suspected HR and to explore the rate of revaccination in a real clinical setting. A retrospective study was performed with a group of preschool children who were evaluated by skin and/or provocation tests (PTs) for the suspected HRs following vaccination. A total of 26 paediatric patients (61.5% male; median age 9 months) with a previous history of suspected vaccine-triggered HR were included. In this group, 69.2% and 38.5% of the patients had a pre-existing atopic disease and an immediate reaction (emerging