Tzank smear is used in diagnosis of which viral infection
[A] CMV
[B] Adenovirus
[C] HSV
[D] Measles
Answer = [C] HSV (Ref: McKee’s Pathology of Skin 4th Ed) Tzank smear prepration: Floor of a vesicle is screped and smeared on a slide and it is stained with Wright’s stain. The diagnostic cell observed in viral infections (herpes simplex, herpes zoster, and varicella) the smears are multinucleated giant cell. These gaint cells are actually an epithelial cell containing numerous nuclei with nuclear molding and viral inclusions that gives the nuclei homogeneous and glassy appearance.
Pemphigus vulgaris (Shows Tzank Cells)
Tzanck smear findings in some important skin disorders are described in below illustration
Tzanck cell is described as a large round keratinocyte with a large
abundant basophilic cytoplasm with perinuclear halo. (See image given)
Toxic epidermal necrolysis (TEN) and staphylococcal scalded skin syndrome (SSSS)
Smears from cases of TEN show necrotizing/degenerating basal cells / with scattered inflammatory cells and fibroblasts.
SSSS show dyskeratotic acantholytic cells with paucity of inflammatory cells in the smears.
Bullous pemphigoid (BP)
The findings of a Tzanck smear are non-specific and characterised by absence of acantholytic cells which serves to rule out pemphigus. Bullous pemphigoid shows paucity of epithelial cells in smears and an abundance of inflammatory cells, particularly ees OST.
Herpes simplex, varicella, herpes zoster:
Shows characteristic multinucleated syncytial giant cells also called as Tzanck giant cells along with presence of acantholytic cells