Most erythema annulare is not contagious. Erythema annulare is a group of skin conditions that manifest themselves primarily as annular erythema, an inflammatory response of the dermis caused by various stimuli, often referred to as vasodilatation and congestion or inflammatory cell infiltration, and is commonly seen in rheumatic immune diseases. Because it is an inflammatory cell infiltrate, most are not contagious. However, some patients with fungal or viral infections may transmit the causative agent to others, but others do not necessarily develop erythema annulare.