Tzanck Smear (Cytology)

Tzanck smear is a fast and practical examination method used in assessing many dermatological conditions — notably cold sores, shingles, pityrosporum folliculitis (which is very often confused with acne), certain bacterial infections of the skin, pemphigus-group diseases that present with fluid-filled blisters, and some skin tumours.

A very small amount of cellular material is taken from the surface of the lesion and, after a special staining process, evaluated under the microscope. The procedure is completed quickly and causes no significant discomfort.

In some conditions the Tzanck smear establishes the diagnosis directly; in others it supports the clinical diagnosis, contributes to the differential diagnosis, or helps rule certain conditions out. It also guides the decision on whether a biopsy is needed in some cases.