This article describes a case of unusual annular erythema-like dermatosis, with histological features of pemphigus foliaceus (subcorneal acantholysis) and IgG antibodies in circulation and bound in vivo to the keratinocyte surface. The reactivity of the antibodies, restricted to human squamous epithelium, was unique, differing from that of all known forms of pemphigus. This also was confirmed by immunoprecipitation. The problem is that these circulating antibodies could be missed if not determined on human substrate. It is to be established whether such cases present a new type of pemphigus or a unknown dermatosis with an autoimmune response of a pemphigus type.