1.3 Virus induced urticarial rashes
Urticaria and acute urticarial rashes go along with up to 50% of all cases with infections of the upper respiratory tract (59 ) and are most often mediated by complement activation and serum sickness induced by viral antigens or secondary mechanisms, due to the interaction of the immune system with viral antigens. This could be also the case in part of the SARS-CoV-2 positive patients with urticarial eruptions (Fig. 7).