Immunoperoxidase technique in diagnosis of oral pemphigus vulgaris: an alternative method to immunofluorescence.

Five cases of oral pemphigus vulgaris, diagnosed on the basis of clinical, histopathologic, and immunopathologic criteria, were selected. Sections were stained with the peroxidase antiperoxidase (PAP) technique of immunocytochemical staining. The findings correlated well with those reported by direct immunofluorescence demonstrating the same intercellular substance (ICS) pattern of staining. Because this staining technique is applied to routinely processed and paraffinized tissue, it may be of particular value to the oral pathologist who often receives formalin-fixed material before the need for immunopathologic studies is recognized. In addition, interpretation does not require specialized microscopy and tissue sections can be stored and retrieved for retrospective study.