Ribonucleic acid COVID‐19 vaccine‐associated cutaneous adverse drug events: a case series of two patients

Lam, M.; Egail, M.; Bedlow, A. J.; Tso, S.

Vaccines are biological preparations that enable their recipients to acquire immunity to a specific infectious disease. All vaccines can associate with cutaneous adverse drug events. Ribonucleic acid (RNA) vaccine was first tested in humans in COVID-19 prevention trials in 2020. The Pfizer-BioNTech COVID-19 vaccine utilises lipid nanoparticles, which act as a vector for the embedded mRNA. In a phase III clinical trial, it was found that local reactions at the injection site are the commonest side effect (84.7%). Other adverse reactions included fatigue, headache, muscle ache, chills, joint pain and fever.1 Jedlowski and Jedlowski (2021) reported a case of recurrent morbilliform rash that developed 48 hours following administration of the Pfizer-BioNTech COVID-19 vaccine on two separate occasions, 21 days apart.2 We hereby report two patients presented with cutaneous adverse drug events following RNA vaccination (Pfizer-BioNTech COVID-19 vaccine).