{Reference Type}: Letter {Title}: Development of immediate and chronic spontaneous urticaria following mRNA COVID-19 vaccination: Tolerability of revaccination and immunological study. {Author}: Teo RXW;Leung BPL;Thong BY;Tan JWL;Chan GYL;Lim XR; {Journal}: Ann Acad Med Singap {Volume}: 53 {Issue}: 1 {Year}: 2024 Jan 30 {Factor}: 8.713 {DOI}: 10.47102/annals-acadmedsg.2023249