The Accuracy of Indirect Immunofluorescence on Sodium Chloride-Split Skin in Differentiating Subepidermal Bullous Diseases

The ARTICLE by Ghohestani et al1in this issue of theArchivesaddresses the diagnostic value of indirect immunofluorescence (IIF) testing on human sodium chloridesplit skin (SSS) in the differential diagnosis of autoimmune subepidermal bullous diseases. In contrast to previous reports,2-7the results of this study cast some doubt on the accuracy of IIF in differentiating epidermolysis bullosa acquisita (EBA) from the pemphigoid group of diseases, including bullous pemphigoid (BP), cicatricial pemphigoid (CP), and herpes gestationis (HG). The article prompts further discussion of a few related questions. First, what defines each of the various bullous diseases? That is, which feature of the disease distinguishes it from another disease with a high or absolute level of certainty? Second, how does a dermatologist obtain the most accurate diagnosis of a subepidermal bullous disease? Third, how helpful is IIF on SSS in differentiating the various sub-epidermal bullous diseases? Consequently, when the