Evaluation of the usefulness of immunofluorescence on Tzanck smears in pemphigus as an aid to diagnosis

Direct immunofluorescence was done on smears taken from 38 cases of bullous dermatoses and oral ulceration. 16 of these had pemphigus. All of the pemphigus cases had positive Tzanck smears and fluorescence of individual acantholytic cells and/or intercellular fluorescence of sheets of cells. Other bullous dermatoses showed no acantholysis or fluorescence. Smears from a series of oral lesions (mainly aphthous ulcers) showed intercellular fluorescence of sheets of cells similar to pemphigus. Therefore smear immunofluorescence cannot be reliably used as a diagnostic test in oral pemphigus.