Delayed inflammatory reaction to hyaluronic acid lip filler after the Pfizer-BioNTech COVID-19 vaccine: A case report.

Hypersensitivity reactions can be a side effect to any vaccine, but they are usually rare. The COVID-19 vaccination may cause hypersensitivity, and several cases of delayed hypersensitivity (DH) to hyaluronic acid (HA) dermal filler have been documented. The current report presents a case of a 36-year-old female patient with DH to HA dermal filler after receiving the Pfizer-BioNTech COVID-19 vaccine. Symptoms, including dryness, swelling, and a painless nodule, appeared after the first and second doses of the vaccine. The patient was treated with intralesional hyaluronidase and triamcinolone in the outpatient clinic. Although HA is relatively safe and routinely used in aesthetic medicine, DH reactions must be considered. Therefore, an appropriate patient history should be obtained, and physicians should provide counselling on the potential reactions to avoid these adverse effects.