Tzanck smear is useful for the diagnosis of

(B) Herpes Virus infection # TZANCK SMEAR is a rapid, fairly sensitive and inexpensive diagnostic method.> Smears are prepared from the lesions, preferably from the base of vesicles and stained with 1% aqueous solution of toludene bleu '0' for 15 seconds.> Multinucleated giant cells with faceted nuclei and homogenously stained 'ground glass' chromatin (Tzanck cells) constitute a positive smear.> Intranuclear type A inclusion bodies may be seen in Giemsa stained smears.> Acantholytic cells present in Pemphigus vulgaris, Senear-Usher syndrome, Pemphigus foliaceous & Pemphigus vegetans