Hyaluronic acid delayed inflammatory reaction after third dose of SARS-CoV-2 vaccine.

[BACKGROUND] Treatments based on hyaluronic acid represent one of the most largely used practice of esthetic medicine. In the literature, it has already been described delayed reaction after vaccine like flu vaccine mediated by T-lymphocytes.

[AIM] We report three cases of dermal filler reactions following mRNA vaccination against SARS-CoV-2; all the patients had received the filler months or even years before the vaccine.

[PATIENTS] Patient one: A 60-year-old female patient that was treated one year ago in the lip developed swelling days after getting mRNA Pfizer Biotech vaccine. She received her booster of Pfizer vaccination one week before. Patient two: A 45-year-old female patient treated in the lip two years before developed angioedema days after getting her booster of Pfizer Biotech vaccine. In this case, it was necessary to prescribe cortisone per os. Patient three: A 40-year-old female patient treated for the nasolabial fold five months before developed erythema and edema after receiving the booster of Moderna Vaccine.

[RESULTS] As demonstrated in our three case reports, even the booster of vaccine can cause delayed inflammatory reactions in patients that have previously received fillers.

[CONCLUSION] Delayed inflammatory reactions in patients that have received filler in the past are uncommon and usually self-limited. Those are the first example reported in the literature of reaction after the booster dose without any previous symptoms.