Pathology Handbook

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Cytology - Tzanck Smear

Alternative Names:

Tzanck Smear for Cytology
Herpes Smear for Cytology

Laboratory:

Anatomical Pathology

Test Code:

NG BRUSH for each smear

Specimen Types:

Skin Scrapings

Container Types:

Slide

Collection & Request Instructions:

Tzanck smear for Cytology

Tzanck smears are taken to detect the multinucleated giant cells which are indicative of Herpes virus. It is preferable for smears to be taken from material scrapped from the edges of the lesion rather than the base which may be necrotic. Smears must be fixed immediately in alcoholic cytology fixative. The smear should not be allowed to air dry.

Tzanck Smear kit A prepared kit containing clean glass slides, a pencil and a container of alcohol fixative is available to assist specimen collection. Kits can be obtained from the Cytology laboratory, which is part of Anatomical Pathology, located on the Ground floor, Main Ward Block, South West.

Instructions for obtaining a Tzanck Smear

· Using pencil, label two glass microscope slides with the patient details (Name and UR). Note: Do not use a pen or permanent marker as the alcoholic fixative will remove the writing

· Choose an intact fresh vesicle and gently clean with an alcohol swab.

· Gently dissect the roof of the blister, breaking the skin or pustule with a scalpel blade.

· Lightly scrape the edges of the vesicle and apply the lesion material to the middle of the glass slide. Smear an area about the 15 - 20mm.

· Place the smear IMMEDIATELY into cytology fixative (green solution).

· Prepare two or more smears if possible

· Return the Tzanck kit containing the prepared smears to the Cytology laboratory (Ground floor, Main Ward Block, South West).

Helpful Hints for taking a Tzanck Smear

· Choose a fresh, representative vesicle

· Pustules and crusted erosions offer much lower yield

· Scrape the lesion sides as the base may be necrotic

· The blister roof and blister fluid will not contain any of the multinucleated giant cells

· If only Crusted Lesions are present; remove the crust and prepare smear of the basal scrapings

· If only Erosive Lesions are present; lightly scrape and prepare smear

Transport Instructions between Sites and/or Laboratories:

Room Temperature

Ensure screw cap on the fixative container is tight. Keep container upright. A request slip must accompany the specimen.

Assay Frequency:

Weekdays

Additional Notes:

A positive Tzanck smear almost always indicates a diagnosis of herpes simplex virus. However, it is important to remember that other members of the herpes family can also result in a positive smear, including: herpes zoster and cytomegalovirus. The clinical manifestation should help with the diagnosis as will a culture for confirmation of HSV.
Tzanck smears have a sensitivity of only 50%, and that is highly dependent upon the age of the lesion. In the event of a negative smear, follow-up cultures where a specimen is available is helpful in this clinical setting.