[The importance of direct immunofluorescence in the diagnosis of oral lichen planus. A clinical study and proposal of new diagnostic criteria].

A series of 40 lesions of various kinds as lichen planus are examined using samples stained with trichromic test. HLA-DR expression with immunoperoxidase technique and direct immunofluorescence using the standard techniques. The aim of the study was to discover the usefulness for diagnosis of direct immunofluorescence, above all in histologically uncertain cases. The results suggest the view that direct immunofluorescence is essential for diagnosis of lichen planus, in all clinical aspects. The author concludes with description of clinical proceeding for differential diagnosis between white and erosive lesions of mouth.