[Skin reactions to the Pfizer-BioNTech vaccine for COVID-19. An Ecuadorian experience].

Objetive: To assess cutaneous reactions after Pfizer-BioNTech COVID-19 vaccine administration.

Methods: A cross-sectional observational study was carried out in health workers belonging to the city of Guayaquil-Ecuador, from March to May 2021. The participants were contacted through a local registry established by the Universidad Espíritu Santo. Frequencies and percentages were used to represent the proportions of nominal variables, while the mean and standard deviation were used for continuous data, given a normal sample distribution.

Results: Local skin reactions were the most frequent, and included redness, edema, and itching. On the other hand, delayed large local skin reactions (generalized rash and pruritus, angioedema, urticaria, eczema, petechiae) were rare and occurred in less than 1.4% of participants, (95% CI = 0.69-1.00). Finally, we did not find cases of anaphylaxis or other life-threatening reactions requiring urgent attention after vaccination.

Conclusions: Our findings suggest that local skin reactions occur in a minority of recipients and are often mild and self-limited.