Several types of antiviral vaccines have been developed to control the spread of the disease since COVID-19 pandemic onset. Currently, many countries are taking measures aimed at increasing vaccination rates for herd immunity formation. However, with increased number of vaccinated individuals, there are more reports of possible adverse events after vaccination, including chronic dermatoses aggravation. The article describes a clinical case of polymorphic dermal vasculitis (hemorrhagic and urticaria types combination) flare up after COVID-19 vaccination in a 73-year-old woman, who was admitted to Department of Dermatology and Venereology (Sechenov University) with complaints of skin rashes in the trunk, upper and lower extremities and intense itching. The presence of comorbid diseases (ischemic heart disease; atrial fibrillation; chronic gastritis; diverticular colon disease; chronic kidney disease) and wide range of drugs intake on a regular basis made it difficult to diagnose. Due to appropriate therapy, clinical remission was achieved 2.5 months after treatment onset as a complete rashes regression on the trunk and upper extremities. The patient was given recommendations to maintain achieved therapeutic effect. The Discussion section provides up to date statistical data on the frequency of skin reactions adverse events after various COVID-19 vaccines administration and discusses possible hypotheses for such side reactions manifestation. Recommendations are given to practicing dermatologist about possible chronic dermatoses exacerbation after vaccine administration. When deciding on vaccination, potential risks should be assessed individually and each patient should be informed accordingly. Despite developed management protocols for patients with a new coronavirus infection, treatment options are still limited. The clinical experience accumulated during the pandemic period shows that COVID-19 vaccination significantly reduces disease severity, minimizes lethal outcome and restrains pandemic outbreak. Therefore, there are no certain dermatological diseases as absolute contraindications to COVID-19 vaccination.