Epidemiology of Autoimmune Bullous Diseases

Immunofluorescence mapping (IFM) is a laboratory technique widely used for the classification of bullous skin diseases. Based on the principles of either direct (DIF) or indirect immunofluorescence (IIF), the method finds its application in acquired immunobullous diseases (AIBD) as well as in different subtypes of the hereditary form of epidermolysis bullosa (EBH). For the diagnosis of the distinct EBH subtypes, the so-called antigen mapping (AgM) demonstrates (1) the level of split formation (intraepidermal, junctional, dermolytic) as well as (2) the expression of a specific structural protein in the skin (normal, reduced, or lacking). In AIBD, the so-called salt split skin test (SSST = direct and indirect antibody mapping, AbM) aids in the differential diagnosis of disorders such as the pemphigoid diseases and various subtypes of epidermolysis bullosa acquisita (EBA) or bullous systemic lupus erythematosus (BSLE). The AbM shows the location of binding of autoantibodies and depicts the level of blistering within the skin (intraepidermal, junctional, dermolytic). Both methods, the AgM and the AbM, reflect important diagnostic information for the clinician with regard to patient consultation about the course (and prognosis) of the respective disease.