C3 and bullous pemphigoid: In cases with IgG and C3 depositions along the basement membrane zone that showed unusual serrated patterns or did not display a predominant intensity for C3, it was not possible to distinguish between bullous pemphigoid and epidermolysis bullosa acquisita because reliable differentiation between these two disease entities requires identifying the exact location of the immune complex’s deposition and the level of the bulla split by immunological tissue-based assays or by detecting specific circulating antibodies in serology [24,25].