In the group of autoimmune bullous disorders, the identification of target antigens enables physicians to differentiate between these frequently clinically similar appearing bullous diseases. Advances in the discovery of new antigens and the subsequent development of an increasing number of sensitive and specific assays for the detection of circulating autoantibodies allow the serological diagnosis in the majority of patients [1]. While the diagnostic gold standard is still the direct IF microscopy of a perilesional biopsy, in the majority of patients, diagnosis can be made by the combination of clinical findings and serology.

A step-wise analysis is usually employed starting with indirect IF microscopy using tissue sections (e.g. monkey esophagus for pemphigus and salt-split skin i.e. normal human skin in which the dermal-epidermal junction was separated by incubation in 1 M NaCl solution) followed by ELISA. At present, six ELISA systems based on the recombinant target antigens are available: desmoglein 1, desmoglein 3, BP180, BP230, type VII collagen, and envoplakin [2–8]. In some patients, additional analyses such as immunoblotting and immunoprecipitation are required to detect autoantibodies against e.g. laminin 332, the ectodomain of BP180, periplakin, and α2 macroglobulin-like 1. These assays are only available in specialized laboratories.